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Biomedical subjects

Z Y Tang

Publications and source records attributed to Z Y Tang.

At least 73 records · Page 4Linked to original sources
PubMed1996

Establishment of a metastatic model of human hepatocellular carcinoma in nude mice via orthotopic implantation of histologically intact tissues.

A highly metastatic LCI-D20 model of human hepatocellular carcinoma (HCC) was obtained via orthotopic implantation of a histologically preserved metastatic tumour selected from 1 of 30 surgical specimens, and had been maintained for 18 passages in nude mice. All mice with transplanted tumours exhibited 100% transplantability and metastatic ability, as well as various manifestations reminiscent of tumour behaviour in HCC patients. These included: local growth, regional invasion, spontaneous metastasis to liver, lymph nodes and lungs, and peritoneal seeding. Histological characteristics of the LCI-D20 tumour were similar to those of the original tumour. Karyotypic analysis revealed heteroploid cells. Immunohistochemically, expression of AFP and HBxAG was shown. Our nude mouse model with its high metastatic rate and short latency period could be an interesting tool for the study of human HCC.

Animals↗
PubMed1996

mRNA levels of nm23 in murine ascites hepatoma (H22) clones with different lymphatic metastatic potential.

Levels of expression of the nm23 gene inversely correlated with metastatic potential in several rodent tumor model systems and human breast carcinoma. In the present study, we examined nm23 mRNA levels in two murine ascites hepatoma models (H22-16A3-F and H22-A2-P) with different metastatic potentials. Metastatic H22-16A3-F (80% metastatic rate) and non-metastatic H22-A2-P clones were both derived from murine ascites hepatoma (H22). We found that a 0.8-kb nm23 transcript was expressed in both cell clones. The nm23 gene was expressed at a higher level in non-metastatic H22-A2-P: approximately 8.6-fold higher than in metastatic H22-16A3-F. The present data suggest that the expression of nm23 mRNA might be associated with metastasis of murine ascites hepatoma (H22), though heterogeneity of nm23 steady-state expression levels among the H22 clones remains to be investigated.

Animals↗
PubMed1996

Long-term results of surgery for small primary liver cancer in 514 adults.

During 1958-1993, 2030 patients with pathologically proven primary liver cancer (PLC) were retrospectively reviewed. Comparison between small PLC (< or = 5 cm, n = 514) and large PLC (> 5 cm, n = 1516) revealed that small PLC had a higher resection rate (92.4% versus 49.1%), lower operative mortality (1.7% versus 5.2%), a higher percentage of single tumour nodules (78.0% versus 53.4%), a higher percentage of well encapsulated tumour (74.5% versus 35.8%) and higher survival rates after resection (5-year, 63.8% versus 36.6%; 10-year, 46.8% versus 28.5%). No significant difference was found between survival following limited resection (n = 440) and lobectomy (n = 34) in patients with small PLC. Re-resection of any subclinical recurrence or solitary pulmonary metastasis after small PLC resection was done in 70 cases. These results indicate that resection is still the modality of choice for treatment of small PLC; limited resection instead of lobectomy was the key to increasing resectability and decreasing operative mortality; re-resection of subclinical recurrence was important to prolong survival further.

Adult↗
PubMed1996

Analysis of the cellular origin of hepatocellular carcinoma by p53 genotype.

The polymerase chain reaction and HaeIII enzymatic digestion were used to study the seventh exon of the p53 gene in 29 primary and recurrent hepatomas in paraffin-embedded samples from 11 patients. The mutation rate of the p53 gene and its genotypes in samples of primary and recurrent tumours and multiple nodules were investigated. The cellular origins of hepatocellular carcinoma were analysed by p53 genotype. p53 mutation rates were found to be 69.0% (20/29) in the primary and recurrent tumours, 58.8% (10/17) in tumours with a single nodule and 83.3% (10/12) in tumours with multiple nodules. The p53 genotypes were found to be different in 6 pairs of primary and recurrent tumours, and another 5 pairs had the same p53 genotypes. The samples with multiple nodules in the same patients had the same p53 genotypes. Seven recurrences were of multicentric origin and four were of unicentric origin. It is suggested that the recurrent lesions developed from both unicentric and multicentric origins.

Adult↗
PubMed1996

Metastatic models of human liver cancer in nude mice orthotopically constructed by using histologically intact patient specimens.

In this study of orthotopic implantation of histologically intact surgical specimens, the authors constructed metastatic models of human hepatocellular carcinoma (HCC) in nude mice. Histologically intact human liver cancer specimens, derived from patients, were implanted directly into the liver of nude mice, and their orthotopic growth and metastases were observed. The transplantability and metastatic rate of two specimen groups (primary and metastatic lesions) were analysed. alpha-Fetoprotein (AFP) was also determined in transplanted tumours by an immunohistochemical method. Orthotopic growth was observed in 14 of 30 transplanted specimens and formation of metastases in 7 cases, which exhibited the variety of clinical behaviours seen in patients with HCC. These behaviours included local growth, regional invasion, spontaneous intrahepatic, lymph node and lung metastasis and peritoneal seeding. In two groups the growth rate of metastatic lesions following implantation was clearly higher than that of primary tumours. Chromosome analysis from locally growing tumours confirmed their morphologically human origin. An immunohistochemical study showed that implanted tumours originating from AFP-positive specimens maintained AFP expression. These results indicated that the animal models should prove valuable for developing new treatment modalities and studying the mechanism of metastasis of human HCC.

Animals↗
PubMed1996

Ablative approach for primary liver cancer: Shanghai experience.

This article summarizes the results of 2018 patients receiving surgical treatment for pathologically proven primary liver cancer (PLC). Special references are made to the role of cryosurgery and cytoreduction for unresectable PLC.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Characteristics and prognosis of primary liver cancer in young patients in China.

To investigate the clinicopathologic characteristics of primary liver cancer (PLC) in young adults, 77 patients aged 35 or younger were compared with 603 patients older than 35 years during the same period. In the young patients, PLC showed: (1) a low incidence detected at mass survey (young 15.6% vs older 28.7%, P < 0.05); (2) a low level of history of hepatitis (young 36.8% vs older 66.3%, P < 0.01); (3) a high incidence of positivity for hepatitis B surface antigen (HBsAg) (young 79.2% vs older 67.6%, P < 0.05); (4) a relatively low incidence of associated cirrhosis (young 64.9% vs older 90.7%, P < 0.01); (5) larger tumor size (PLC > 5 cm; young 87.0% vs older 73.0%, P < 0.01); and (6) a more advanced stage of the disease according to the TNM classification (stage III; young 29.9% vs older 18.2%, P < 0.05). It is suggested that hepatitis B virus (HBV) may play an important role in the development of PLC without associated liver cirrhosis in young patients. Close periodic surveillance of young adults who are positive for HBsAg is important to detect PLC at an early stage.

Adult↗
PubMed1995

[Study of HCV infection and viremia in patients with posttransfusion hepatitis in China].

One hundred and sixty-nine patients with posttransfusion hepatitis (PTH) were investigated for etiology with serological and PCR methods. Our result showed that HCV was the major causative agent of PTH in this study. A part of patients (24/169) were also HBV markers positive. Three patients were negative for all detected viral markers, looking forwards to progressive study. Anti-HCV was detectable from 7 days to one year after onsetting of clinical symptoms, average time 54.62 days. HCV RNA could be detected in early time of HCV infection ( 6 to 20 days later), average time 8.72 days. A follow-up study of 84 patients showed that all patients remained anti-HCV positive during the observation for 1.5 -- 3 years, but their HCV viremia had three forms: transient, persistent or intermittent. The interaction between HCV and HBV by their superinfection was unknown, awaiting further study.

Adolescent↗
PubMed1995

Infectivity and risk factors of hepatitis C virus transmission through sexual contact.

HCV infection among heterosexuals with multiple partners and family members of patients with hepatitis C, and HCV RNA in the body fluid of these patients were investigated. The results showed that the HCV infection in heterosexuals with multiple partners, which was related to sexual activity, was much higher than that of healthy pregnant women. The HCV RNA in the saliva, semen or vaginal discharge of patients with hepatitis C was at detectable level. Among the patient's relatives, none of the children but 2 spouses were found to be infected with HCV. We concluded that sexual contact might play some role in HCV transmission.

Adolescent↗
PubMed1995

Secondary structure of holo- and apo-aminoacylase from prediction, circular dichroism, and FT-Raman spectroscopy.

The secondary structures of native (Holo-) and Zn(2+)-free (Apo-) aminoacylase were examined by circular dichroism (CD) and Fourier transform Raman (FT-Raman) spectroscopic techniques and prediction methods. Quantitative analysis of the conformationally sensitive amide I band indicates that Holo- and Apo-enzyme contain 19.3 and 17.2% helical structure, respectively. Far-UV CD spectra of Holo- and Apo-enzyme show that they contain 20.1 and 17.6% alpha-helix, respectively. Secondary structure prediction of aminoacylase indicates that it contains approximately 20.9% alpha-helical structure including 10 alpha-helix segments. The results show that after removal of Zn2+ in aminoacylase, the extent of ordered structure was decreased markedly. The conformation at or near the active site of aminoacylase may contain more ordered structure and the presence of Zn2+ may help to maintain the catalytically active conformation at the active site.

Amidohydrolases↗
PubMed1995

Observation of changes in peripheral T-lymphocyte subsets by flow cytometry in patients with liver cancer treated with radioimmunotherapy.

An analysis of lymphocyte subsets was performed in 24 patients with surgically verified unresectable hepatocellular carcinoma (HCC). In all cases, the hepatic artery was cannulated and ligated and a single dose of 131I-Hepama-1 monoclonal antibody (MAb) was infused through a hepatic artery catheter. Blood samples were obtained before infusion and 1 month post-infusion. The results indicated that the CD3+ T-cells (pan T-cells) were normal, whereas the CD4+ T-cells (T-helper/inducer cells) decreased and the CD8+ T-cells (T-suppressor/cytotoxic cells) increased significantly in comparison with the control group. So the CD4+:CD8+ ratio declined markedly. One month post-radioimmunotherapy (RIT), the T-cell subsets did not change, but CD4+, CD8+ and the CD4+:CD8+ ratio differed significantly between patients with and without sequential resection. The changes in the T-cell subsets were closely related to tumour capsule status and the human anti-murine antibody (HAMA) response, but no relationship was found between the tumour and administration of a moderate dose of radioimmunoconjugate. Therefore, determination of changes in the T-lymphocyte subsets and the CD4+:CD8+ ratio could be used as clinical and prognostic indicators in patients who have received RIT. Furthermore, RIT did not affect the distribution of T-cell subsets in patients with HCC.

Animals↗
PubMed1995

Multimodality treatment in advanced primary liver cancer.

This paper reports the long-term results of multimodality treatment in 1639 patients with pathologically proven primary liver cancer (PLC) over the past three decades. In this series, patients in subclinical stage constituted 23.9% (391/1639), moderate stage 63.0% (1032/1639), and late stage 13.2% (216/1639). There were 381 patients (23.2%) with small PLC (< = 5 cm). The PLC was coexistent with liver cirrhosis in 86.4% (1416/1639). The 5-year survival after resection of PLC was 45.5% for the whole series (n = 896), and 62.7% for patients with a tumor < = 5 cm (n = 345). The 5-year survival after hepatic artery ligation (HAL) and hepatic artery infusion (HAI) (n = 124) was 18.1%, while the 5-year survival after palliative resection (n = 175) was 12.5%. The 5-year survival of 40 patients receiving second-look resection after cytoreduction therapy was 68.4%. Cryosurgery was performed on 107 PLC patients, the 5-year survival being 22.0% for the whole series, and 48.8% for the 32 patients with small PLC. The 5-year recurrence rate after resection was 55.3%. The 5-year survival after reoperation for recurring tumor (n = 90) was 40.8%. It is suggested that surgery remains the modality of choice, and it plays a more important role in the treatment of PLC. The results of palliative surgery (HAL + HAI) seem better than those of palliative resection; combined multimodality treatment and second-look resection, and new surgical techniques might offer hope for unresectable advanced PLC.

Adolescent↗
PubMed1994

Recurrence after resection of alpha-fetoprotein-positive hepatocellular carcinoma.

The long-term prognosis of surgery for hepatocellular carcinoma (HCC) is not yet satisfactory, the main reason being the high recurrence rate. The authors report the results of a long-term follow-up of 308 patients with HCC who became alpha-fetoprotein-(AFP)-negative after resection between 1975 and 1991. By March 1992, there was recurrence in 134 patients (43.5%). The 1-, 3-, 5- and 10-year recurrence rates were 9.2%, 38.8%, 54.9% and 85.0%, respectively. The 5-year survival rate was 49.7% for patients who had undergone a second hepatic resection (n = 48). Analysis of factors influencing postoperative recurrence indicated that patients subjected to mass survey, with a lower gamma-glutamyltransferase level, at an early stage of TNM classification, with a tumour of less than 5 cm, without tumour embolus, and with postoperative immunotherapy had a lower incidence of recurrence. It is concluded that the earlier the disease is diagnosed, the less the recurrence rate; adjuvant immunotherapy may reduce postoperative recurrence, and the early detection and resection of a recurrent tumour are important to prolonging survival further after curative resection of HCC.

Adult↗
PubMed1994

Human anti-(murine Ig) antibody responses in patients with hepatocellular carcinoma receiving intrahepatic arterial 131I-labeled Hepama-1 mAb. Preliminary results and discussion.

Human anti-(murine Ig) antibody (HAMA) responses were monitored in 32 patients with unresectable hepatocellular carcinoma (HCC) undergoing radioimmunotherapy using 131I-labeled anti-HCC monoclonal antibody (Hepama-1 mAb) intrahepatic arterial infusion. Dosages of Hepama-1 mAb ranged from 5 mg to 20 mg and the mAb was radiolabeled with 0.74-4.00 GBq (20-108 mCi) 131I (4-6 mCi/mg). T lymphocyte subsets were examined before and after radioimmunotherapy in 24 patients. In this series, 34.4% (11/32) of patients developed HAMA within 2-4 weeks after the infusion. All patients with a negative HAMA response (n = 14), had CD4+ T lymphocyte subsets (T helper/inducer) much lower than those of the HAMA-positive (n = 10) patients and the control group (n = 40) (P < 0.01) prior to infusion. The sequential resection and survival rates in the HAMA-negative group were also lower than that of the HAMA-positive group. Thus, the determination of T lymphocyte subsets might help to predict the HAMA response in HCC patients during radioimmunotherapy.

Adult↗
PubMed1994

[Mutation of p53 gene and expression of alphafetoprotein during hepatocarcinogenesis].

To investigate the expression of mutant p53 protein (mP53) and alpha-fetoprotein (AFP) during hepatocarcinogenesis, we detected immunohistochemically the specimens from 4 cases of normal human liver, 5 of cirrhosis, 5 of adenomatous hyperplasia (AH), and 16 of hepatocellular carcinoma (HCC) (by Edmondson classification. The 4 cases with normal liver showed negative mP53 and AFP. Four of the 5 cirrhosis cases were positive for mP53 and AFP. In 5 AH cases, 4 were positive for mP53 and AFP. In the 4 cases of grade I HCC, 2 were positive for mP53 and AFP. In the 6 cases of grade II HCC, 4 were positive for mP53 and AFP. In the 6 cases of grade III HCC, 1 showed mP53 positive staining but negative AFP, and 2 were negative for mP53 but positive for AFP, while 3 were negative for both mP53 and AFP. The results indicated that the mutation of p53 gene occurred in the early stage of hepatocarcinogenesis, and may be correlated with the initiation of hepatocarcinogenesis, and that mutant p53 protein probably related to the reactivation of AFP gene.

Adult↗
PubMed1994

[Preparation of monoclonal antibody directed against hepatitis B virus X protein and detection of reactive antigen in hepatocellular carcinoma].

A mouse monoclonal antibody directed against hepatitis B virus (HBV) X protein (HBxAg) was prepared. The antibody was used to screen by immunohistochemistry 50 liver tissue sections from patients with hepatocellular carcinoma (HCC), and 15 patients with chronic active hepatitis (CAH). 28 of 50(56%) samples were HBxAg positive in tumor tissues. The positive rates of HBxAg only in tumor tissues or in adjacent nontumor tissues were 24% and 16%. HBsAg was detected in 16% of cases in tumor tissues and 74% in surrounding nontumor tissues. In CAH samples, the positive rates of HBxAg and HBsAg were 6.6% and 73.3%. HBcAg was only detected in nontumor surrounding liver tissues, the positive rates being 18%. In CAH samples, no HBcAg was detected. The results showed that HBxAg is a common marker in liver tissue from patients with HBV-related HCC. The findings of HBxAg in the absence of detectable HBsAg and HBcAg in the liver tissues suggested that HBxAg could be independent of HBV replication and implied that the synthesis of HBxAg may be directed from integrated HBV DNA templates. It is possible to use antiHBx monoclonal antibody as a carrier for the targeting therapy of HCC.

Animals↗
PubMed1994

[Targeting treatment of human HCC xenografts implanted in nude mice using bifunctional antibody HC-1 combined with mitomycin C].

Bifunctional antibody (BFA) HC-1 possessing one binding site for mitomycin C (MMC) and a companion site directed against human hepatocellular carcinoma (HCC) cell membrane was constructed by chemical conjugation of two Fab' fragments of McAb MMC-1 and McAb HCMP-1. BFA could be specifically attached to tumor xenograft of nude mice bearing human HCC and thus simultaneously capture mitomycin C. The attachment of these complexes was detected by radioimmunoimaging in nude mice bearing human HCC using 131-I labelled BFA HC-1. Clear imaging of the tumor was obtained in 6 days after i.p. injection. On the 8th day after the injection, tumor/liver (T/L) ratio was 8.04 +/- 0.45. When the BFA HC-1 was used to be combined with MMC for the targeting treatment of human HCC implanted in nude mice, the highly significant suppression of tumor growth was achieved. After two months of treatment, xenografts of 40% (4/10) mice disappeared and 60% (6/10) of the mice survived. Those mice treated only with MMC became more and more sick even if the grafted tumors shrank, and all of them died within 2 months after therapy. The controls were treated with nonspecific IgG. Tumors grew very fast, and most of the controls died in 1 month after the first injection. The results suggest that BFA HC-1 could concentrate MMC on the human HCC cells, and it is a kind of suitable carrier for the targeting treatment of human HCC.

Animals↗