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T J Liu

Publications and source records attributed to T J Liu.

At least 73 records · Page 4Linked to original sources
PubMed1997

99Tcm-HMPAO-labelled white blood cell scans to detect acute appendicitis in older patients with an atypical clinical presentation.

Forty-nine patients (age > 50 years) with an acute abdomen and suspected appendicitis, but with atypical findings, were included in the study. After the intravenous injection of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) labelled white blood cells (WBCs), serial anterior images of the abdomen and pelvis were obtained after 30, 60, 120 and 240 min. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen equal to or greater than bone marrow activity was considered positive. Twenty-five patients had positive WBC scans, all of whom underwent laparotomy. Twenty-three of these patients were shown to have appendicitis; the other 2 did not. The other 24 patients had a negative WBC scan, 2 of whom underwent laparotomy and were shown to have appendicitis; the other 22 patients did not undergo surgery and showed no evidence of appendicitis during follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values of WBC scans for diagnosing appendicitis were as follows: 92.0%, 91.7%, 91.8%, 92.0% and 91.7% respectively. In conclusion, 99Tcm-HMPAO-labelled WBC scans provide a rapid and highly accurate method for diagnosing appendicitis in older patients with equivocal clinical findings.

Abdomen, Acute↗
PubMed1997

Optimal surgical strategy for potentially curable serosa-involved gastric carcinoma with intraperitoneal free cancer cells.

BACKGROUND: Radical gastrectomy with systematic lymphadenectomy (RG) remains controversial in the treatment of gastric carcinoma. On the other hand, the prognosis of gastric carcinoma, in the presence of intraperitoneal free cancer cells, is poor. The optimal surgical strategy for serosa-involved gastric carcinoma with intraperitoneal free cancer cells remains undefined. STUDY DESIGN: A prospective study of intraperitoneal cytologic washing was conducted on 134 patients with potentially curable serosa-involved gastric carcinoma who underwent RG. During the same period, 28 patients with resectable tumors who received palliative simple gastrectomies because of the presence of gross incurable conditions (eg, multiple hepatic metastases, peritoneal carcinomatosis, or extra-abdominal metastasis) were used as controls. RESULTS: Intraperitoneal free cancer cells were found in 26 patients (19.4 percent). Compared with the remaining 108 patients without free cancer cells, there were no significant differences in the clinicopathologic characteristics and pathologic stages. No patients died after palliative resection, but five patients died after RG. The patients with free intraperitoneal free cancer cells had a poorer long-term prognosis after RG than those without free cancer cells (p < 0.0001). The prognosis for such patients was similar to the prognosis of those who underwent palliative resection. CONCLUSIONS: A peritoneal washing cytologic examination is mandatory before resection for potentially curable serosa-involved gastric carcinoma. When free cancer cells appear in the washing fluid, the cancer is incurable. Simply gastrectomy without additional lymphadenectomy is the optimal strategy for treatment.

Aged↗
PubMed1997

Cytotoxic effects of recombinant adenovirus p53 and cell cycle regulator genes (p21 WAF1/CIP1 and p16CDKN4) in human prostate cancers.

PURPOSE: Overexpressing or restoring the basal levels of tumor suppressor genes in cancer cells can suppress tumorigenicity of cancer cells. In this communication, we compared tumor suppressive activities of three well-defined tumor suppressive genes (p53, p21WAF1/CIP1, and p16CDKN2) delivered individually to prostate cancer cells with adenoviral vector (Ad). MATERIALS AND METHODS: Efficacy of growth inhibition by recombinant adenoviruses bearing p53, p21WAF1/CIP1, or p16CDKN2 (Ad5CMV-p53, Ad5CMV-p21, Ad5CMV-p16) genes were tested in vitro on androgen-dependent (LNCaP) and androgen-independent (C4-2, DU-145, and PC-3) human prostate cancer cells, ex vivo and in vivo on PC-3 tumor. RESULTS: Ad5CMV-p53 was observed to exert the greatest growth inhibitory action on all of the cell lines tested; inhibition appeared to be cytolytic. In comparison to control Ad5CMV-PA added samples, the growth inhibitory action of Ad5CMV-p21 and Ad5CMV-p16 appeared to be cytostatic. Ad5CMV-p53 is more effective than Ad5CMV-p16 and Ad5CMV-p21 in inhibiting the tumor "take" rate. A similar order of antitumor activity was observed when recombinant adenoviruses were injected intratumorily to previously established PC-3 tumors in vivo. CONCLUSION: p53 is the most effective tumor suppressor gene to target human prostate cancer.

Adenoviruses, Human↗
PubMed1997

Sarcomatoid carcinoma of the small intestine: a case report.

Sarcomatoid carcinoma of the small intestine is a very rare tumor. Only limited cases have been reported in the literature. The tumor is more malignant than the usual adenocarcinoma of the small intestine. Here we report a 59-year-old female patient who was referred from a local hospital after suffering persistent hematochezia, abdominal pain and distention for three months. Because of persistent intestinal obstruction and bleeding, reoperation at our hospital was performed. A huge tumor, originating from the ileum and with multiple liver and bone metastasis, was found. Palliative resection of the tumor with two segments of the small intestine and sigmoid colon was carried out. Pathology confirmed the diagnosis of sarcomatoid carcinoma. She died two months after operation.

Carcinoma↗
PubMed1997

Head and neck squamous cell growth suppression using adenovirus-p53-FLAG: a potential marker for gene therapy trials.

The recombinant wild-type p53 adenovirus has been proven effective against the growth of human head and neck squamous cell cancer (SCCHN) cell lines iir vitro and in a nude mouse model. The addition of a FLAG peptide sequence was used in this study, along with the p53 adenovirus vector as a marker of the site of the gene therapy activity. It provides clear evidence of the exogenous gene product within the transduced carcinoma cells. No alterations in transcription or translation of the p53 gene product were noted with the addition of the FLAG sequence to the original p53 adenovirus vector. Immunohistochemical analysis displayed simultaneous expression of the p53 and FLAG proteins in the infected cells. The p53 protein remained localized to the nucleus, whereas the FLAG protein was additionally noted in the cytoplasm. In vitro growth suppression assays and in vivo microscopic residual tumor model experiments in nude mice showed a similar tumoricidal effect with the p53-FLAG adenovirus vector to that with the previously studied p53 adenovirus vector without the addition of the FLAG sequence. We conclude that the addition of the FLAG octapeptide sequence allows identification of those cells that have been affected by the molecular therapy independent of the endogenous gene expression of the cells. This novel molecular tracer may prove useful in characterizing infection efficiency and in gene therapy trials.

Adenoviridae↗
PubMed1996

Secretory production of bioactive recombinant human granulocyte-macrophage colony-stimulating factor by a baculovirus expression system.

The proliferation and differentiation of hematopoietic cells are stimulated by a group of glycoproteins called colony stimulating factors (CSFs). Previously, we found that the human hepatoma cell line HA22T/VGH secreted a high level of human granulocyte-macrophage colony-stimulating factor (hGM-CSF). The cDNA of hGM-CSF, including the signal peptide sequence, was amplified from the total RNA of HA22T/VGH by a reverse-transcription polymerase chain reaction and was cloned into the pUC18 vector. After confirming the nucleotide sequence, the cDNA was inserted into a pVL1393 baculovirus transfer vector. The recombinant baculovirus carrying hGM-CSF cDNA was generated by co-transfecting the hGM-CSF recombinant transfer vector and BaculoGold baculovirus DNA into the Sf9 insect cells. The expected hGM-CSF transcript was detected in the recombinant virus-infected Sf9 cells. The conditioned media of the infected cells were analyzed by a slot-blot immunoassay. The results indicate that the infected insect cells produced and secreted hGM-CSF. According to colony forming assay, a maximum titer of 2.1 x 10(6). U ml-1 of hGM-CSF in the medium was obtained on the third day after infection.

Amino Acid Sequence↗
PubMed1996

Adenovirus-mediated p16/CDKN2 gene transfer induces growth arrest and modifies the transformed phenotype of glioma cells.

The p16 (MTS1/CDKN2) gene localized at the 9p21 chromosomal region encodes for a cell cycle inhibitor protein and is altered in many human cancers. The frequency of p16 alterations in gliomas exceeds 50%. To restore the missing wild-type p16 gene efficiently in glioma cells an adenovirus vector carrying the full length coding sequence of the wild-type p16 cDNA, Ad5RSV-p16, was constructed. Three human glioma cell lines, U251 MG, U-87 MG and D54 MG, that did not express endogenous p16/CDKN2 gene and were easily infected with adenovirus vectors were selected for these experiments. Introduction of the Ad5RSV-p16 in these malignant glioma cell lines directed the biosynthesis of functional p16 protein in the majority of the exposed cells, significantly inhibited cell growth, influenced cell morphology and modified the transformed phenotype of cells including the ability to form colonies in soft agar. Flow cytometric studies revealed that the majority of the Ad5RSV-p16 infected glioma cells were arrested in the G0-G1 phases of the cell cycle. These results suggest that p16/CDKN2 inactivation is a significant factor in the genesis and progression of gliomas and that the restoration of the wild-type p16 protein could have clinical and therapeutic utility.

Adenoviridae↗
PubMed1996

Gene therapy for head and neck cancer. Comparing the tumor suppressor gene p53 and a cell cycle regulator WAF1/CIP1 (p21).

OBJECTIVE: To compare the efficacy of the tumor suppressor gene wild-type p53 with that of cell-cycle regulator WAF1/CIP1 as single-agent gene therapy for squamous cell carcinoma of the head and neck. EXPERIMENTAL METHODS AND DESIGN: Recombinant cytomegalovirus-promoted adenoviruses containing the wild-type p53 or WAF1/CIP1 (p21) genes were transiently introduced into squamous cell carcinoma of the head and neck cell lines. Standard Western blot analysis was used to determine expression in these cells of the proteins encoded by these genes. A nude mouse xenograft model of squamous cell carcinoma of the head and neck was used to investigate the in vivo efficacy of the repeated gene therapy interventions. RESULTS: Western blot analysis showed marked induction of the WAF1/CIP1 tumor suppressor gene product by both the p21 adenovirus and the wild-type p53 adenovirus (as a secondarily transcribed product). In vitro growth curves demonstrated that the wild-type p53 adenovirus significantly inhibited cell growth in these cell lines, whereas direct induction of the p21 gene product did not. Repeated infection with wild-type p53 adenovirus significantly reduced the size of established subcutaneous tumors, whereas infection with a replication-defective viral control did not. CONCLUSION: Wild-type p53 adenovirus exhibits substantial in vitro and in vivo tumor suppressor activity in squamous cell carcinoma of the head and neck cell lines. This tumor suppression is not a function of the induced WAF1/CIP1 (p21) transcriptional product. Further studies are required to investigate the potential for induction of apoptosis by gene therapy.

Adenoviruses, Human↗
PubMed1996

Effects and limitations of prolonged intermittent ischaemia for hepatic resection of the cirrhotic liver.

Intermittent clamping of the hepatic pedicle during hepatectomy may reduce operative bleeding, but its limitations and long-term effects on the cirrhotic liver are unknown. Eighty-three patients with cirrhosis undergoing hepatectomy with repeated clamping for 15 min and declamping for 5 min were divided into three groups based on total clamping duration: group 1 less than 40 min (39 patients); group 2 40-80 min (28); group 3 more than 80 min (16). Larger tumours were associated with longer ischaemia times (P = 0.002), longer operating times, greater operative blood loss and increased blood transfusion requirements (P < 0.001), and resulted in higher postoperative levels of serum transaminases and lactic dehydrogenase (P < 0.001). Operative morbidity and mortality rates, and the late hepatic failure rate, were not affected. The longest total ischaemia time was 204 min but the uppermost time limit for hepatic ischaemia remains to be determined.

Alanine Transaminase↗
PubMed1996

Hepatic resection of hepatocellular carcinoma in cirrhotic livers: is it unjustified in impaired liver function?

BACKGROUND: Resection for hepatocellular carcinoma in patients with cirrhosis and impaired liver function is usually unjustified because of higher surgical risks and poorer long-term prognosis. METHODS: A retrospective comparison of the background and resectional results of patients with cirrhosis and hepatocellular carcinoma was carried out between those with preoperative indocyanine green 15-minute retention rate of 20% or greater (group A, impaired function group, n = 36) and those with indocyanine green 15-minute retention rate of 10% or less (group B, normal function group, n = 34). RESULTS: The group A patients had significantly lower serum albumin level and higher serum bilirubin level, longer prothrombin time, higher incidence of associated esophageal varices, and poorer Child's classifications for cirrhosis. Although the tumor diameter in both groups was similar (A, 6.9 versus B, 7.1 cm; p = 0.94), the resected liver amount in group B was greater (227.4 versus 473.2 gm; p = 0.038) because of a greater extent of liver resection (p < 0.001) and a wider surgical margin (0.34 versus 1.85 cm; p < 0.0001). The amount of operative blood loss and blood transfusion, operative morbidity, and operative mortality were not different between the two groups. The pathologic characteristics and staging were also comparable. The 5-year disease-free and actuarial survival rates of groups A and B were 30.9% and 29.6% (p = 0.16) and 45.2% and 33.4% (p = 0.11), respectively. CONCLUSIONS: If the amount of resected nontumorous liver parenchyma could be reduced, resection of hepatocellular carcinoma in selected patients with cirrhosis and impaired liver function is still justified in spite of a narrow surgical margin.

Adult↗
PubMed1996

Factors influencing postoperative morbidity, mortality, and survival after resection for hilar cholangiocarcinoma.

UNLABELLED: OBJECTIVE; Morbidity and mortality involved in the resection of hilar cholangiocarcinoma were reviewed retrospectively. The clinicopathologic and laboratory parameters that might influence the patient's survival also were re-evaluated. SUMMARY BACKGROUND DATA: Although much progress has been made in the diagnosis and management of hilar cholangiocarcinoma, long-term outlook for most patients remains poor. Surgical resection is usually prohibited because of its local invasiveness, and most patients can only be managed by palliative drainage. Recently, many surgeons have adopted a more aggressive resection with varying degrees of success. Several prognostic factors in bile duct carcinoma have been proposed; however, no reports have specifically focused on resected hilar cholangiocarcinoma and its prognostic survival factors using multivariate analysis. METHODS: The clinical records and pathologic slides of 49 cases with resected hilar cholangiocarcinoma were reviewed retrospectively. Twenty clinical and laboratory parameters were evaluated for their correlation with postoperative morbidity and mortality, whereas 31 variables were evaluated for their significance with postoperative survival. Variables showing statistical significance in the first univariate analysis were included in the following multivariate analysis using stepwise logistic regression test for factors affecting morbidity and mortality and Cox stepwise proportional hazard model for factors influencing survival. RESULTS: There were 5 in-hospital deaths, and the cumulative 5-year survival rate in 44 patients who survived was 14.9%, with a median survival of 14.0 months. Multivariate analysis disclosed that co-existent hepatolithiasis and lower serum asparate aminotransferase levels (<90 U/L) had a significant low incidence of postoperative morbidity, whereas a serum albumin of less than 3 g/dL was the only significant factor affecting mortality. Regarding survival, univariate analysis identified eight significant factors: 1) total bilirubin > or = 10 mg/dL, 2) curative resection, 3) histologic type, 4) perineural invasion, 5) liver invasion, 6) depth of cancer invasion, 7) positive proximal resected margin, and 8) positive surgical margin. However, multivariate analysis disclosed total bilirubin > or = 10 mg/dL, curative resection, and histologic type as the three most significant independent variables. CONCLUSIONS: Surgical resection provides the best survival for hilar cholangiocarcinoma. An adequate nutritional support to increase serum albumin over 3 g/dL is the most important factor to decrease postoperative mortality. Moreover, preoperative biliary drainage to decrease jaundice and a curative resection with adequate surgical margin are recommended if longer survival is anticipated. Patients with well-differentiated adenocarcinoma seem to survive longer compared to those with moderately or poorly differentiated tumors.

Adult↗
PubMed1996

Tc-99m HMPAO-labeled WBC scans to detect appendicitis in women.

Fifty female patients with acute abdomen and suspected appendicitis but atypical findings were included in this study. After intravenous injection of Tc-99m HMPAO-labeled WBCs, serial anterior abdominal/pelvic images at 30, 60, 120, and 240 minutes were obtained by a gamma camera. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen with equal to or greater than bone marrow activity was considered as a positive scan. Thirty patients had positive WBC scans and underwent laparotomy, 28 had proven appendicitis, and 2 were not related to appendicitis. Twenty patients had negative WBC scans, 2 patients underwent laparotomy and were proved to have appendicitis. The remaining 18 patients did not undergo surgery and revealed no evidence of appendicitis after follow-up. The overall sensitivity, specificity, accuracy, and positive and negative predictive values for WBC scans to diagnose appendicitis is 93.3%, 90.0%, 92.0%, 93.3%, and 90.0%, respectively. In conclusion, Tc-99m HMPAO-labeled WBC imaging provides a rapid and highly accurate method for diagnosis of appendicitis in female patients with equivocal clinical examinations.

Adolescent↗
PubMed1996

Mobile cecum syndrome: a report of two cases.

Mobile cecum syndrome is characterized by chronic right lower quadrant pain with the evidence of neither appendicitis nor other pathological findings at operation. Two cases of mobile cecum syndrome are reported; both had intermittent right lower quadrant cramping pain for months. One had received appendectomy because of chronic right lower quadrant pain at another hospital about nine months before admission here. The symptoms did not improve postoperatively, and the patient underwent laparotomy under impression of partial intestinal obstruction. The other patient underwent laparotomy under impression of chronic appendicitis. At surgery, both were found to have cecum and ascending colon were not attached to the posterior parietal wall, and cecopexy was performed. They have now been symptom free for one year. Cecopexy appears therefore to be an effective method of treatment of mobile cecum syndrome.

Abdominal Pain↗
PubMed1996

Hepatic angiomyolipoma: a report of two cases.

Two cases of rare hepatic angiomyolipoma are reported. Both represented with slight abdominal discomfort. The first patient complained of abdominal fullness, and had a normal physical examination and laboratory data. The second came with epigastralgia. Tenderness over right upper quadrant was noted and positive hepatitis B antigen was found. Ultrasound demonstrated hyperechoic hepatic lesion in both. Although diagnosis of hepatic angiomyolipoma was suspected by the radiological findings of ultrasound, CT, MRI, and angiography, it was confirmed by the histological presence of three mesenchymal components: abundant vessels, mature fat cells and smooth muscle cells. For fear of the coexistence of hepatocellular carcinoma, especially given the high prevalence area of Taiwan, surgical intervention was recommended if liver function permitted. Successful treatment was achieved by hepatic resection in both cases.

Adult↗
PubMed1996

Detection of k-ras point mutations in codons 12 and 13 in non-small cell lung cancers.

Point mutations of the K-ras gene have been reported in a wide variety of human tumors. By using polymerase chain reaction followed by direct DNA sequencing, we screened for point mutations at codons 12 and 13 of the K-ras gene in specimens obtained from fresh frozen tumors in 38 patients with non-small cell lung cancers. Point mutations were detected in two of 38 (5.3%) resected non-small cell lung cancers. Both of them were G to T transversions. One patient was found to have a K-ras codon 13 point mutation (GGC to TGC, gly to cys), while the other had a codon 12 point mutation (GGT to GTT, gly to val). Based on the limited numbers in this study, we found that the frequency of K-ras point mutations in codons 12 and 13 among Asian patients with lung adenocarcinomas was lower than that detected among Caucasian patients.

Adult↗
PubMed1996

Evaluation of topical gene therapy for head and neck squamous cell carcinoma in an organotypic model.

The organotypic (raft) culture system has been shown to be a useful model for examining the effects of biochemical manipulations on various epithelial cell types, using in vitro conditions that simulate the in vivo environment of the tissue of origin. To investigate this method as a model for topical gene therapy, we cultured the oral head and neck squamous cell carcinoma cell line TR146 on fibroblast-containing collagen gels at the air-medium interface and assessed the efficiency of transduction of a topically applied adenoviral vector containing beta-galactosidase cDNA. Diffuse expression of -galactosidase activity in multiple cell layers demonstrated effective penetration of the vector. Transduction efficiency and therapeutic activity of a replication-defective recombinant adenovirus containing wild-type p53 cDNA linked to a FLAG marker (AdCMV-p53-FLAG) were then assessed in TR146 organotypic cultures transduced by topical application. Twenty-four, 48, and 72 h after transduction, the cultures were harvested, and residual cell number and FLAG peptide expression were determined. The number of cells in p53 transduced cultures was significantly reduced in comparison to controls at all three time points (P < 0.001), which resulted from the induction of apoptosis as determined by in situ DNA end labeling. In addition, the FLAG peptide was expressed diffusely in the residual cells, further confirming effective transduction and expression of the exogenous gene products throughout multiple layers. We conclude that the organotypic culture is an effective in vitro model for assessing the efficacy of topically applied gene therapy on head and neck squamous carcinomas and premalignancies.

Adenoviridae↗
PubMed1995

Apoptosis induction mediated by wild-type p53 adenoviral gene transfer in squamous cell carcinoma of the head and neck.

Cancer gene therapy strategies for inducing apoptosis in solid tumors may allow contemporary medicine to reassess its management of these cancers. We demonstrated previously that overexpression of the wild-type p53 gene in squamous cell carcinoma of the head and neck cell lines via adenovirus-mediated gene transfer suppressed growth both in vitro and in vivo. Here, we characterize the mechanism of the growth suppression by the exogenous p53 gene as a consequence of programmed cell death (apoptosis). One of the cell lines used in this study, Tu-138, harbors a mutated p53 gene, whereas the other cell line, MDA 686LN, possesses a wild-type p53 gene. DNA fragmentation was detected by electrophoresis in both cell lines after infection with the wild-type p53 adenovirus, Ad5CMV-p53. With the use of the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling method, 4.4% of the remaining viable Tu-138 cell population was identified as apoptotic as early as 15 h after inoculation with Ad5CMV-p53. The percentage of apoptotic cells increased to 31% at 22 h. In contrast, only 10% of the viable MDA 686LN cells (wt-p53) had undergone apoptosis 30 h after Ad5CMV-p53 infection, although the percentage of apoptotic cells rapidly increased to 60% at 48 h after infection. For in vivo analysis of apoptosis, nude mice in which squamous cell carcinoma of the head and neck cell lines had been implanted s.c. had exogenous wt-p53 transiently introduced to the tumor cells via Ad5CMV-p53 2 days later. In situ end labeling clearly illustrated apoptosis in the tumor cells. These results suggest that wt-p53 plays an important role in the induction of apoptosis in human head and neck cancer cell lines and that selective induction of apoptosis in cancer cells can be further explored as a strategy for cancer gene therapy.

Adenoviridae↗