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Biomedical subjects

Y Shao

Publications and source records attributed to Y Shao.

At least 91 records · Page 5Linked to original sources
PubMed1999

[Effect of liposomal albendazole on the ultrastructure of Echinococcus granulosus cysts in mice].

AIM: To observe the histopathological changes of Echinococcus granulosus cysts in mice treated with liposomal albendazole and co-administration with cimetidine by light microscopy and electron microscopy. METHODS: An oral dose of liposomal ABZ with different formulations was given at 200 mg/kg.d. Cimetidine was administered daily at an oral dose of 100 mg/kg.d. Sixty-seven mice were orally given different drugs six days per week for a total of twelve weeks. RESULTS: The histopathological changes indicated that there were significant differences (P < 0.01) between treated groups and control group. The degeneration and necrosis of E. granulosus cysts were marked in liposomal albendazole combined with cimetidin group. CONCLUSION: Liposomal albendazole was more effective against E. granulosus cyst than albendazole. Cimetidine had an apparent synergistic effect when given in combination with liposomal albendazle.

Albendazole↗
PubMed1999

[Cloning the representative strains of China HIV-1 subtypes B, C and E for heteroduplex mobility analysis (HMA)].

OBJECTIVE: To clone the HIV-1 env gene and establish the HMA reagents suitable for use with the Chinese HIV strains. METHODS: Using Nest-PCR technique, we amplified env gene from representative strains which contain the most proximate consensus of China HIV-1 subtypes B, C and E. The genes were then cloned into pGEM-Teasy vector for HMA subtyping. RESULT: The env gene of representative strains of China HIV-1 subtypes B, C and E were amplified and cloned into plasmids. The plasmids were used in HMA and compared with those standard env gene of other countries. The heteroduplex bands obtained with ours env genes were more proximate to homoduplex bands. The homogeneity of the corresponding China HIV-1 subtypes with standard TH14(B), IND868(C), MA959 (C) and TH22(E) are 90.2%(B), 88.3%(C), 83.7(C)% and 92.3%(E) respectively. CONCLUSION: The HMA reagents we established in this study have higher sensitivity in HMA analysis for China HIV-1 strains when compared with the international HMA reagents. The HMA reagents also provide new reference reagents for UNAIDS HIV isolation network.

Acquired Immunodeficiency Syndrome↗
PubMed1999

[Sequence analysis of human immunodeficiency virus type 1 tat gene among the long-term HIV infected non-progressoris in Yunnan province].

OBJECTIVE: HIV-1 tat gene is one of its regulatory genes necessary for its replication. This study is to explore whether the variation of tat gene influences the AIDS progress of HIV infected individual. METHODS: We carried out investigation on tat gene of HIV among the long term HIV infected non-progressors and the commonly infected individuals. Mononuclear cells of peripheral blood were isolated and cellular DNA was extracted. Nested PCR method was used to amplify tat gene and their sequences were analyzed. RESULTS: Blood were collected from 22 HIV infected individuals, of which 11 cases were infected with B subtype strains based on previous env gene analysis and belonged to long term non-progressors according to clinical features and immunology. The other 11 cases were common HIV infection of which 5 subtype B and 6 subtype C were found. Both long term non-progressor group (subtype B) and the commonly HIV infectedly group (subtype B) had constantly four amino acids different from that of international B subtype consensus sequence The both groups clustered randomly on the phylogenetic tree. In commonly HIV infected subtype C group there were 6 amino acids different from that of international subtype C. The variation inside the tatgene of common subtype C group was small. CONCLUSIONS: There was no regular variation and significant difference between long term HIV infected non-progressive group and commonly HIV infected subtype B group. There is no evidence showing that progressive speed of AIDS correlated with the tat sequence profile of HIV-1.

Amino Acid Sequence↗
PubMed1999

[The prognostic value of virology and immunology markers in Chinese HIV-1 infected people].

OBJECTIVE: To study the prognostic value of virology and immunology markers in Chinese HIV-1 infected people and their correlation. METHODS: We studied 190 HIV infected people/AIDS patients' samples from China. Plasma viral load, P24 antigen, virus culture, CD4 positive T lymphocyte (CD4) count and CD8 positive T lymphocyte(CD8) count were tested. Test groups were divided according to clinical staging diagnosis from physicians. The data were analyzed in aspects of their relations with clinical status and correlations among all the above markers. RESULTS: Plasma viral load, CD4 count and CD4/CD8 ratio showed significant difference between asymptomatic stage and symptomatic stages (P < 0.01), also between asymptomatic and AIDS stages(P < 0.001). Virus culture positive rate increased significantly from asymptomatic to symptomatic stage. No significant clinical change was observed associating with P24 antigen positive rate. CD8 count decreased slightly when AIDS occurred (P < 0.001). Close correlation was observed between plasma viral load, CD4 count and CD4/CD8 ratio. CONCLUSION: Viral load, CD4 count and CD4/CD8 ratio are useful indicators to AIDS prognosis and virus culture can be a supplementary marker. p24 antigen detection seems no diagnostic value to disease progress. The significance of CD8 change will be further studied.

Biomarkers↗
PubMed1998

The complete DNA sequence and analysis of the large virulence plasmid of Escherichia coli O157:H7.

The complete DNA sequence of pO157, the large virulence plasmid of EHEC strain O157:H7 EDL 933, is presented. The 92 kb F-like plasmid is composed of segments of putative virulence genes in a framework of replication and maintenance regions, with seven insertion sequence elements, located mostly at the boundaries of the virulence segments. One hundred open reading frames (ORFs) were identified, of which 19 were previously sequenced potential virulence genes. Forty-two ORFs were sufficiently similar to known proteins for suggested functions to be assigned, and 22 had no convincing similarity with any known proteins. Of the newly identified genes, an unusually large ORF of 3169 amino acids has a putative cytotoxin active site shared with the large clostridial toxin (LCT) family and proteins such as ToxA and B of Clostridium difficile . A conserved motif was detected that links the large ORF and the LCT proteins with the OCH1 family of glycosyltransferases. In the complete sequence, the mosaic form can be observed at the levels of base composition, codon usage and gene organization. Insights were obtained from patterns of DNA composition as well as the pathogenic and 'housekeeping' gene segments. Evolutionary trees built from shared plasmid maintenance genes show that even these genes have heterogeneous origins.

Amino Acid Sequence↗
PubMed1998

Characterization and functional analysis of the cis-autoproteolysis active center of glycosylasparaginase.

Glycosylasparaginase is an N-terminal nucleophile hydrolase and is activated by intramolecular autoproteolytic processing. This cis-autoproteolysis possesses unique kinetics characterized by a reversible N-O acyl rearrangement step in the processing. Arg-180 and Asp-183, involved in binding of the substrate in the mature enzyme, are also involved in binding of free amino acids in the partially formed substrate pocket on certain mutant precursors. This binding site is sequestered in the wild-type precursor. Binding of free amino acids on mutant precursors can either inhibit or accelerate their processing, depending on the individual mutants and amino acids. The polypeptide sequence at the processing site, which is highly conserved, adopts a special conformation. Asp-151 is essential for maintaining this conformation, possibly by anchoring its side chain into the partially formed substrate pocket through interaction with Arg-180. The reactive nucleophile Thr-152 is activated not only by deprotonation by His-150 but also by interaction with Thr-170, suggesting a His-Thr-Thr active triad for the autoproteolysis.

ATP-Binding Cassette Transporters↗
PubMed1998

Distinct effects of allogeneic blood transfusion on splenocyte cytokine production after hemorrhagic shock.

UNLABELLED: Allogeneic blood transfusion is known to be immunosuppressive in the settings of cancer and transplantation, but the contribution of blood transfusion to immunomodulation after hemorrhage is unknown. Our purpose was to determine the influence of allogeneic blood transfusion upon cytokine profiles following hemorrhagic shock, using a model which approximates the clinical setting. METHODS: Male C3H/HeN mice were hemorrhaged via femoral arterial catheters to a mean arterial pressure (MAP) of 35 +/- 5 mm Hg, which was maintained for 1 h. Mice were resuscitated with autologous blood (auto BT) or allogeneic blood (allo BT) from Balb/c mice (both equivalent to volume of shed blood), and crystalloid (2X the volume of shed blood)-infused at 0.05 ml/min. Animals were sacrificed at 1, 2, and 5 days postshock, and splenocytes were cultured for 24 h with anti-CD3 antibody. Supernatants were assayed for IL-2, IL-6, IL-10, and gamma-IFN by ELISA. RESULTS: Regardless of transfusion status, hemorrhagic shock resulted in increased IL-6 and gamma-IFN by Day 2 postshock. Distinct cytokine alterations after allogeneic transfusion were as follows. IL-2: transient elevation of splenocyte IL-2 production in the shock + allo BT group (P < 0.005 vs. shock + auto BT) at Postshock Day 2. IL-6: suppression in IL-6 production in the shock + allo BT group by Postshock Day 5 (P < 0.05 vs. shock + auto BT). IL-10: persistently elevated IL-10 production following shock + allo BT (Day 1, P < 0.001 vs. shock + auto BT; Day 5; P < 0.05 vs. shock + auto BT). gamma-IFN: elevation in gamma-IFN production by Day 5 in the shock + allo BT group (P < 0.0005 vs. shock + auto BT). CONCLUSIONS: Allogeneic blood transfusion results in distinct alterations in splenocyte production of IL-2, IL-6, IL-10, and gamma-IFN after hemorrhagic shock. This model reflects the clinical usage of blood products and demonstrates some of the immune alterations after transfusion.

Animals↗
PubMed1998

Inhibitory activity of boswellic acids from Boswellia serrata against human leukemia HL-60 cells in culture.

Four major triterpene acids including beta-boswellic acid (1), 3-O-acetyl-beta-boswellic acid (2), 11-keto-beta-boswellic acid (3), and 3-O-acetyl-11-keto-beta-boswellic acid (4) were isolated from the gum resin of Boswellia serrata and examined for their in vitro antitumor activity. They inhibited the synthesis of DNA, RNA and protein in human leukemia HL-60 cells in a dose dependent manner with IC50 values ranging from 0.6 to 7.1 microM. Among them, compound 4 induced the most pronounced inhibitory effects on DNA, RNA and protein synthesis with IC50 values of 0.6, 0.5, and 4.1 microM, respectively. The effect of 4 on DNA synthesis was found to be irreversible. Compound 4 significantly inhibited the cellular growth of HL-60 cells, but did not affect cell viability.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Neutron yields from 435 MeV/nucleon Nb stopping in Nb and 272 MeV/nucleon Nb stopping in Nb and Al.

Neutron fluences were measured from 435 MeV/nucleon Nb ions stopping in a Nb target and 272 MeV/nucleon Nb ions stopping in targets of Nb and Al for neutrons above 20 MeV and at laboratory angles between 3 degrees and 80 degrees. The resultant spectra were integrated over angles to produce neutron energy distributions and over energy to produce neutron angular distributions. The total neutron yields for each system were obtained by integrating over the angular distributions. The angular distributions from all three systems are peaked forward, and the energy distributions from all three systems show an appreciable yield of neutrons with velocities greater than the beam velocity. Comparison of the total neutron yields from the two Nb + Nb systems suggests that the average neutron multiplicity decreases with decreasing projectile energy. Comparison of the total yields from the two 272 MeV/nucleon systems suggests that the total yields show the same dependence on projectile and target mass number as do total inclusive neutron cross sections. The data are compared with Boltzmann-Uehling-Uhlenbeck model calculations.

Aluminum↗
PubMed1998

Left atrial systolic and diastolic function accompanying chronic rapid pacing-induced atrial failure.

The objective of this study was to examine the hypothesis that long-term, rapid atrial pacing produces a model of atrial systolic and diastolic dysfunction but does not alter ventricular function. Eight dogs were atrially paced at 400 beats/min (3:1-5:1 ventricular response) for 6 wk and subsequently instrumented with left atrial (LA) and left ventricular (LV) sonomicrometers and micromanometers. Data were compared with those from six sham-operated controls at matched heart rates and mean LA pressures of 10 mmHg. Dogs with rapid pacing had slightly greater LA volume (10.3 +/- 4.0 vs. 7.9 +/- 4.4 ml) and reduced ejection fraction (2.2 +/- 1.4 vs. 13.0 +/- 4.0, P < 0.05), systolic ejection rate (0.3 +/- 0.1 vs. 2.8 +/- 1.2 vol/s, P < 0.05), and reservoir fraction (0.07 +/- 0.04 vs. 0.35 +/- 0.06, P < 0.05) compared with controls. LA diastolic chamber stiffness was greater after rapid atrial pacing than before (stiffness constant kc, 5.7 +/- 2.3 vs. 3.4 +/- 0.6, P < 0.05), and the ratio of transesophageal echo-determined pulmonary venous systolic to diastolic integrated flow (a measure of relative reservoir to conduit function of the LA) was less in rapidly paced dogs compared with control dogs (0.41 +/- 0.19 vs. 0.68 +/- 0.23, P < 0.05). In contrast, rapid atrial pacing did not influence LV systolic performance or lusitropy, because the LV pressure time derivative and the time constant of LV relaxation were similar in both groups. In this model of isolated atrial myopathy, increased atrial stiffness and enhanced conduit function compensate for impaired atrial booster pump and reservoir functions.

Animals↗
PubMed1998

[Subtype and sequence analysis of the C2-V3 region of gp120 genes among HIV-1 strains in Sichuan province].

Nine DNA fragments of HIV-1 env gene were amplified by PCR from uncultured peripheral blood mononuclear cells (PBMCs) obtained from HIV-1 sero-positive intravenous drug users (IDUs) in Sichuan province, in mid 1996. Their C2-V3 region (about 450 bp) was sequenced. Sequence analysis showed that there were two HIV-1 subtypes B and C, with 1.4% and 2.6% gene divergence inside each subtype, in Sichuan. The 5 subtype B strains, when comparing with sequences of several reference HIV-1 strains, were found similar to these identified in Thailand, Myanma and Yunnan province. The nucleotide sequence divergence between them was ranged from 3.6% to 4.3%. Meanwhile, the 4 subtype C strains except sc3, were most close to those found in India as well as in Yunnan province, and both their nucleotide sequence divergence was 3.1%. The sc3 strain belonged to subtype C but had larger genetic distance, between 10.1%-17.2%. Above results suggested a recent epidemic of both subtype HIV-1 strains in Sichuan provine and they were very close to those identified in Yunnan province: The subtype C strain of sc3 is special and its source remains not clear.

China↗
PubMed1998

[Diagnosis and treatment of male breast carcinoma].

OBJECTIVE: To evaluate the diagnosis and treatment of male breast carcinoma. METHODS: Thirty-two male breast carcinoma cases were studied. The median age was fifty-four years old. The diagnosis, treatment and prognosis for male breast carcinoma were studied. RESULTS: Clinical stage of the patients: I, 7 patients; II, 17 patients; III, 7 patients; IV, 1 patient. Of the 32 carcinomas, 31 patients had mass in the breast. Positive lymph nodes were found in 57.1% of the patients. The 5-year survival rate was 65.6% for all patients, 68.4% for patients undergone radical mastectomy, 66.7% for those undergone modified radical mastectomy and 57.1% for the others. CONCLUSION: The optimal treatment for male breast carcinoma is modified radical mastectomy combined with radiotherapy, chemotherapy and endocrine therapy.

Adenocarcinoma↗
PubMed1998

[Determination of avermictin in avermictin tablet by high performance liquid chromatography].

A method for the separation and determination of avermictin in avermictin tablet by reversed-phase high performance liquid chromatography (RP-HPLC) was developed. Operating conditions were as follows: TSK-GEL C18 column, 250 mm x 4.6 mm i.d., MeOH-H2O (75:25, V/V) mobile phase with a flow rate of 1.0 mL/min, and UV detection at 245 nm. The results showed that the active constituents avermictin B1a and B1b can by separated effectively. The relative standard deviations were 2.56% and 1.31%, respectively (n = 6). The method is accurate, rapid and simple, and provides a scientific basis for industrial production and quality control of avermictin tablet.

Animals↗
PubMed1998

[Treatment and prognosis of 33 patients with recurrent retroperitoneal soft tissue sarcomas].

OBJECTIVE: To investigate the treatment and the prognosis of patients with recurrent retroperitoneal soft tissue sarcomas. METHOD: The clinical data of 33 patients, treated for recurrent retroperitoneal soft tissue sarcomas from 1972 to 1996 were analyzed retrospectively. RESULT: Complete tumor resection was performed for 17 patients (51.5%) with tumor recurrence for the first time. 2, 3, 1 patients underwent multiple organs resection respectively when the sarcoma relapsed initially, secondly and thirdly. Fourteen patients were given adjuvant radiotherapy and chemotherapy postoperatively. Twenty-nine patients were followed for up for 6 to 12 months. Fifteen (51.7%) of them died. Seven of them survived beyond 5 years and 2 over 10 years. The 1-, 3-, and 5-years survival rate was 85.7%, 54.9% and 42.3% respectively. CONCLUSION: Surgery is effective in improving the survival rate of patients with recurrent retroperitoneal soft tissue sarcomas, including those with repeatedly recurrent sarcomas. Multiple organ resection could be beneficial to the curative resection rate. Adjuvant radiotherapy and chemotherapy might improve the local control of relapsed sarcomas to some extent.

Adult↗
PubMed1998

[Construction of the prokaryotic expression plasmid pYNenv encoding the gp120 env gene of human immunodeficiency virus type 1 of yunnan strain].

The recombinant envelope protein of human immunodeficiency virus type 1(HIV-1) of Chinese Yunan epidemic strain was expressed in E. coli for confirming the antigenic domains of the protein. The recombinant prokaryotic expressive plasmid pYNenv was constructed by inserting the env DNA fragment which encode the gp120 of HIV-1 Yunnan strain into pBV220. The env DNA fragment was obtained by nested polymerase chain reaction with the HIV-1 infected patients peripheral blood macrophage and monocyte genomes from Yunan HIV-1 epidemic area as template. The recombinant plasmid pYNenv was confirmed by restriction enzyme analysis. The recombinant protein was expressed in E. coli DH10b by pYNenv after vibration culture at 30 degrees C for 20 hours then at 42 degrees C for 5 hours and confirmed by SDS-PAGE electrophoresis. The protein can specifically react with the serum of HIV-1 infected patient from Yunan epidemic area by Western blot assay. The result showed that the recombinant protein can be used as antigen for detection of HIV-1 membrane glycoprotein antibody as well as for the further study of the role of envelope protein in pathology.

Adult↗