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Biomedical subjects

Yan Zhao

Publications and source records attributed to Yan Zhao.

194 records · Page 11Linked to original sources
PubMed2002

[In vitro regulation of HLA and B7 expression in multidrug-resistant breast cancer cells].

OBJECTIVE: To study the modulation of the expressions of human leucocyte antigen (HLA) and co-stimulatory molecules B7 (CD80, CD86) in multidrug-resistant (MDR) breast cancer cells. METHODS: The MDR phenotype MCF-7/ADR cells were treated with recombinant human interferon (IFN)-alpha2b (rhIFN-alpha2b) at different doses for varied length of time, and the expressions of HLA and B7 were determined by flow cytometry (FCM) and compared with those of non-treated cells. Statistical analysis was performed using SPSS10.0 software. RESULTS: At the doses smaller than 1x10(3) IU/ml, rhIFN-alpha2b did not exhibit significant inhibition on MCF-7/ADR cell growth, but HLA and B7 expressions were enhanced in a dose- and time-dependent fashion and significant up-regulation occurred 24 h after 400 IU/ml rhIFN-alpha2b treatment. Treatment with rhIFN-alpha2b at the doses of 100, 400, 800 IU/ml respectively for 24 h produced significant increases in the positive cell ratios for HLA class I expression (P<0.05), HLA-DR expression (P<0.005) and B7-2 expression (P<0.05), while changes in B7-1 expression was not obvious (P>0.05). The mean relative linear fluorescence intensity (RLFI) of HLA class I was also significantly increased (P<0.001) but alterations in the mean RLFI of HLA-DR and B7 were not significant. CONCLUSIONS: rhIFN-alpha2b within the dose range from 400 to 800 IU/ml can effectively enhance the expression of HLA and B7 molecules, suggesting that it may have the potential to reverse immune tolerance of breast cancer cells. Cytokine treatment may be effective in reversing immune tolerance caused by down-expression of HLA and B7.

Antigens, CD↗
PubMed2002

[Diagnosis of hepatocellular carcinoma with bone metastasis using fine needle aspiration biopsy: report of 2 cases].

The clinical presentations and imaging characteristics of hepatocellular carcinoma (HCC) are usually various and complex. This article reported 2 cases of HCC with the initial symptoms being bone metastasis that did not exhibit typical clinical manifestations or distinct feature in liver imaging, without elevated serum alpha-fetoprotein. The diagnoses were certified by fine needle aspiration biopsy, which is recommended for differential diagnosis in cases of complex HCC with bone metastasis, to avoid liver biopsy and surgical bone biopsy.

Adult↗
PubMed2002

[Continuous hepatic artery infusion chemotherapy and chemoembolization for treatment of patients with liver metastases from colorectal cancer].

BACKGROUND & OBJECTIVE: Although previous studies showed that hepatic artery chemoembolization or continuous intravenous with infusion chemotherapeutic agent can improve the effects of the treatment of liver metastases from colorectal cancer, the results remained unsatisfactory because of the lower concentration of local chemotherapeutic agent. This study was designed to evaluate the efficacy of continuous hepatic artery infusion chemotherapy and chemoembolization for the treatment of liver metastases from colorectal cancer. METHODS: A total of 26 patients with liver metastases from colorectal cancer were treated 93 times by continued hepatic artery infusion chemotherapy and chemoembolization. Infusion chemotherapy alone was performed 42 times, and infusion chemotherapy combined with chemoembolization were 51 times. Chemotherapeutic agents used were Adriamycin 30 mg/m2 d1, Mitomycin 6 mg/m2 d1, Cisplatin 80 mg/m2 d1, or Etoposide 60 mg/m2 d1-3, Calcium folinate 200 mg/m2, d1-3, and Fluorouracil 2,500 mg/m2. Adriamycin and Mitomycin were mixed with lipiodol ultra-fluid for chemoembolization. Response rates were assessed by CT and B ultrasonic wave scanning. RESULTS: An overall response rate [CR + PR] of the cases was 57.69%. The median survival period was 11.5 months. The 0.5, 1, 2, 3, and 5-year survival rate was 92.31%, 76.92%, 38.46%, 23.07%, and 3.85%, respectively. There was no severe side effect or complication. CONCLUSION: Continuous transcatheter hepatic artery infusion chemotherapy and chemoembolization are useful methods for the treatment of the patients with liver metastases from colorectal cancer, which may the life quality and life span of the patients.

Adult↗
PubMed2002

[Combination chemotherapy with Taxol and cisplatin for 57 patients with non-small cell lung cancer by intraartery and intravenous infusion].

BACKGROUND & OBJECTIVE: Although previous studies showed that intravenous infusion chemotherapy combined with Taxol and cisplatin (DDP) can improve the effects of the treatment of advanced non-small cell lung cancer (NSCLC), the results remained unsatisfactory because of the lower concentration of local chemotherapeutic agent. This study was designed to administrate the chemotherapeutic agents through the local artery and to evaluate the efficacy of the intraartery (IA) and the intravenous (i.v.) infusion chemotherapy combined Taxol with cisplatin (DDP) in the treatment of NSCLC. METHODS: Fifty-seven patients with advanced NSCLC were enrolled and randomized into two groups. Group A (27 patients) was given by IA chemotherapy consisting of Taxol 135 mg/m2 and DDP 80 mg/m2 within 3 hours in the first day. Group B (30 patients) was given by i.v. chemotherapy consisting of Taxol 135 mg/m2 and DDP 80 mg/m2 within 3 hours in the first day. The patients in two groups were repeatedly treated every 3-4 weeks for at least 2 cycles. RESULTS: The recent effect was evaluated by the CT or X-ray results. Of the 57 patients, 1 case acquired complete response, 29 partial response. The overall response rate was 52.63% with 66.67% (18/27) in group A and 40.00% (12/30) in group B. The median TTP was 5.5 months in group A and 4.0 months in group B. The median survival time was 13.5 months in group A and 10.5 months in group B. The 0.5, 1, 2, and 3-year survival rates were 85.18%, 66.67%, 48.15%, and 18.51% months in group A, respectively. The 0.5, 1, 2, and 3-year survival rates were 70.00%, 53.33%, 30.00%, and 6.67% months in group B, respectively. The main side effects were myelosuppression, gastrointestinal reactions and peripheral neuropathy. They could be effectively treated with large amount of vitamines, antacid, guastil, white blood cell stimulating drugs and liquid compensation. CONCLUSION: The artery infusion Taxol and DDP chemotherapy is one of the useful methods in the treatment of NSCLC patients. The local response rate in the patients treated by IA may be higher than those treated by i.v.

Adult↗
PubMed2002

[Fluoride in the environment and brick-tea-type fluorosis in Tibet].

To explore whether endemic fluorosis in Tibet is related to local factors, an epidemiological survey of fluorosis was conducted in 3 districts in Tibet. The survey used the WHO and FAO established "Guideline for the study of dietary intake of chemical contaminants" and the Horowitz suggested criteria for children dental fluorosis examination. The fluorine in the local environment of the 3 selected districts was studied in detail. The possible fluorine sources examined indicated that only the brick-tea carried a high content of fluoride; water, other food materials, and fuel contents were insignificant. The children daily fluorine intake was high, where Naqu was 8.03 mg, Lahsa was 6.93 mg, Dingri was 7.68 mg. All the dietary fluoride was come from the brick-tea processed foods: the buttered-tea and zamba, these two contributed 99.74%, 98.70% and 99.60% of their daily fluorine intake respectively. The dental fluorisis index indicated that Naqu and Dingri were severe epidemic and Lahsa was moderate epidemic. The endemic fluorosis that occurs in Tibet was essentially due to heavy consumption of foodstuffs prepared with brick-tea, however, the high altitude, harsh living conditions, and poor nutritional status aggravated the fluorosis. Brick-tea type fluorosis is a new type of fluorosis recently discovered in China. Compared with the drinking water type and coal combustion type of fluorosis, it covered extensive area, more covert, and difficult to control. Decrease the fluorine content of brick-tea might be the most promising measure.

Altitude↗
PubMed2002

[Umbilical metastasis from malignant neoplasms of pelvic and abdominal cavity with 3 cases analysis].

OBJECTIVE: To study the incidence, spreading path, prognosis and treatment of the umbilical metastasis Sister Mary Joseph nodule (SMJN) from malignancies. METHODS: To analyse the clinical feature from 3 cases of SMJN and to review pertinent literatures. RESULTS: Three cases SMJN were come from advanced primary peritoneal carcinoma in case 1, recurrent mucinous ovarian papillary adenocarcinoma in case 2 after primary cytoreductive surgery and systemic chemotherapy and case 3 with recurrent endometrial carcinoma. All patients received umbilical resection and the umbilical metastasis was confirmed pathologically, while case 3 was diagnosed adenocarcinoma spreading by fine needle respiration before the surgery. The mean survival was 63 months following surgery or chemotherapy or radiotherapy, case 1 died of advanced malignancy, while case 2 and case 3 were still alive 58 and 44 months, respectively. CONCLUSIONS: Although the incidence being low, SMJN was the important sign of one of the vast metastatic malignancy and has grave prognosis. Umbilical resection should be performed on some patients of SMJN with relative good condition, and chemotherapy or radiotherapy should also performed accordingly.

Abdominal Neoplasms↗
PubMed2002

[Atypical manifestation of hepatocellular carcinoma by triple-phase spiral CT scan].

OBJECTIVE: To analyze the cause of atypical manifestation of hepatocellular carcinoma (HCC) in triple-phase spiral CT enhanced scan. METHODS: Triple-phase spiral CT scan was performed in 75 patients with HCC. The hepatic arterial phase (HAP), portal venous phase (PVP) and delayed phase (DP) images were started at 25 to 30 s, 65 to 70 s and 3 tp 5 min after injection of contrast medium. The contrast enhanced patterns of lesion were observed and analyzed. RESULTS: Ninety-two lesions were found in 75 patients. Typical enhanced findings such as hyperdense in HAP and hypodense in PVP and DP was found in 60 of 92 lesions. Atypical enhanced findings were observed in the other 32 lesions. Fourteen of 32 atypical enhanced lesions were hyperdense in HAP and isodense in PVP, of which 8 were seen in liver cirrhosis and 3 in fatty liver. In DP, 10 were hypodense and 4 still isodense. Eight of the 32 lesions were hyperdense both in HAP and PVP, of which 6 were seen in fatty liver. In DP, 3 were isodense and 5 were hypodense. Six of 32 lesions were isodense in HAP which became hypodense in PVP and DP. Four of 32 lesions were all hypodense in HAP, PVP and DP. CONCLUSION: Multiple atypical enhanced manifestations are present by triple-phase spiral CT scan in HCC. Pattern of blood supply, scanning technique and pathophysiologic status are usually the cause of these findings.

Adult↗
PubMed2002

[Pulmonary thromboembolism in systemic lupus erythematosus: clinical analysis of 11 cases].

OBJECTIVE: To investigate the diagnosis and therapy of systemic lupus erythematosus (SLE) patients with pulmonary thromboembolism (PTE). METHODS: 11 hospitalized cases were reviewed retrospectively in PUMC Hospital during January 1984-July 2001. RESULTS: All 11 cases were suffered from severe active lupus with PTE. The SLE-DAI (SLE-disease active index) was 21.9 +/- 4.9. 7 cases had first onset of progressive Raynaud phenomenon. Anti-RNP antibody was positive in 73% of the cases. Echocardiogram revealed medium-severe pulmonary hypertension. When PTE was found, while 6 cases had started with smaller to medium dose of prednisone treatment, which was 20-30 mg/d, and other 4 cases received no prednisone. Only 1 received large dose of prednisone and immunosuppressor. Large dosage of prednisone, immunosuppressor with or without anticoagulant were given to those 6 and 4 patients after final diagnosis, respectively. 6 of 7 cases showed relieved Raynaud phenomenon while 4 cases hemoptysis were disappeared, echocardiogram had confirmed that pulmonary artery pressure decreased in 4 cases. [(31.7 +/- 12.4) mmHg]. 5 cases survived, 3 were dead and 3 failed to be followed up. CONCLUSIONS: Patients of SLE with PTE are liable to be misdiagnosed or missed-diagnosed, The risk factors are active-SLE, progressive Raynaud phenomenon, and symptoms of thromboembolism, positive anti-RNP antibody and mild-medium pulmonary artery hypertension. Combined therapy of present available measures like large dose of prednisone, immunosuppressors and anticoagulant are highly recommended.

Adult↗
PubMed2001

Use of a vector based on Potato virus X in a whole plant assay to demonstrate nuclear targeting of Potato spindle tuber viroid.

Potato spindle tuber viroid (PSTVd) is a covalently closed circular RNA molecule of 359 nucleotides that replicates within the nucleus of host cells. To determine how this small, highly structured RNA enters the nucleus, we have developed a virus-based, whole plant in vivo assay that uses green fluorescent protein (GFP) as the reporter molecule. The coding region of GFP was interrupted by insertion of an intron derived from the intervening sequence 2 of the potato ST-LS1 gene. A cDNA copy of the complete PSTVd genome was, in turn, embedded within the intron, and this construct was delivered into Nicotiana benthamiana plants via a vector based on Potato virus X. The intron-containing GFP subgenomic RNA synthesized during virus infection cannot produce a functional GFP unless the RNA is imported into the nucleus, where the intron can be removed and the spliced RNA returned to the cytoplasm. The appearance of green fluorescence in leaf tissues inoculated with constructs containing a full-length PSTVd molecule embedded in the intron indicates that nuclear import and RNA splicing events did occur.

Active Transport, Cell Nucleus↗
PubMed1999

beta-Silyl and beta-Germyl Carbocations Stable at Room Temperature.

Stable carbocations have been prepared at room temperature with benzene as solvent and tetrakis(pentafluorophenyl)borate (TPFPB) as anion by the addition of solvated triethylsilylium TPFPB or of tributylgermylium TPFPB to 1,1-diphenylethene. These carbocations are stabilized by sigma conjugation with nonadjacent group 14 atoms and respectively constitute stable saturated beta-silyl and beta-germyl carbocations. NMR parameters, including the (29)Si chemical shift, the (13)C chemical shifts of the cationic, aryl, and methylene carbons, and the one-bond (13)C-(1)H coupling constant of the methylene group adjacent to the group 14 element, define the distribution of positive charge between carbon and (through sigma conjugation) silicon or germanium. The extent of hyperconjugation is estimated quantitatively by comparison with models. The NMR parameters indicate that the cations are open rather than bridged.

Journal Article↗
PubMedDate not supplied

Multiple virus infections in the honey bee and genome divergence of honey bee viruses.

Using uniplex RT-PCR we screened honey bee colonies for the presence of several bee viruses, including black queen cell virus (BQCV), deformed wing virus (DWV), Kashmir bee virus (KBV), and sacbrood virus (SBV), and described the detection of mixed virus infections in bees from these colonies. We report for the first time that individual bees can harbor four viruses simultaneously. We also developed a multiplex RT-PCR assay for the simultaneous detection of multiple bee viruses. The feasibility and specificity of the multiplex RT-PCR assay suggests that this assay is an effective tool for simultaneous examination of mixed virus infections in bee colonies and would be useful for the diagnosis and surveillance of honey bee viral diseases in the field and laboratory. Phylogenetic analysis of putative helicase and RNA-dependent RNA polymerase (RdRp) encoded by viruses reveal that DWV and SBV fall into a same clade, whereas KBV and BQCV belong to a distinct lineage with other picorna-like viruses that infect plants, insects and vertebrates. Results from field surveys of these viruses indicate that mixed infections of BQCV, DWV, KBV, and SBV in the honey bee probably arise due to broad geographic distribution of viruses.

Amino Acid Sequence↗
PubMedDate not supplied

Current progress of China's free ART program.

China's Free ART Program was initiated in 2002 as an emergency response to save and improve the lives of AIDS patients living mainly in impoverished rural regions of central China. With little experience in HIV/AIDS treatment and care and resource limitations, China's efforts to provide widespread access to free antiretroviral therapy has been a process fraught with difficulty. However, the Free ART Program is progressing from an emergency response to a standardized treatment and care system. The development of national guidelines, training programs, a laboratory support network, a national patient database, programs for special populations such as children and patients living with co-infections, and operational research has improved the scope and quality of the free treatment program. As of June 30, 2005, a total of 19,456 patients in 28 provinces, autonomous regions, and special municipalities had received free ART. Challenges stemming from the nature of China's health system and patient population persist, but with strong government support and a diverse set of resources, China has the capacity to overcome these challenges and to provide nationwide access to high quality treatment and care.

Anti-Retroviral Agents↗
PubMedDate not supplied

BZLF1 controlled by family repeat domain induces lytic cytotoxicity in Epstein-Barr virus-positive tumor cells.

BACKGROUND: BZLF1, an EBV (Epstein-Barr virus) immediate early gene, is required for EBV lytic replication that causes the death of host cells. EBNA1, the product of EBV latent gene, binds to the family repeats (FR) of the origin of replication (Orip) regulating EBV replication. MATERIALS AND METHODS: A vector pFR-Z (BZLF1 controlled by FR domain of EBV) was constructed and transfected into EBV-positive 5-8F and-negative HNE3 nasopharyngeal carcinoma cells and BZLF1-induced cytotoxicity was tested. RESULTS: EBNA1 expression was detected in 5-8F but not HNE3 cells and, in agreement, pFR controlled luciferase expression was activated in 5-8F cells but inhibited in HNE3 cells. Gardella gel assay demonstrated that pFR-Z effectively induced EBV lytic replication in 5-8F but not HNE3 cells. The lytic cytotoxicity was confirmed by a diminished cell survival and the induction of lytic proteins EA-D and gp125. The cytotoxicity was also strikingly enhanced by addition of GCV (gancyclovir) that kill cells with lytic form EBV. CONCLUSION: pFR-Z is a specific gene therapy vehicle for EBV-positive carcinomas.

Cell Line, Tumor↗