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Y Fong

Publications and source records attributed to Y Fong.

At least 127 records · Page 7Linked to original sources
PubMed1997

Comparison of phased-array and body coils for MR imaging of liver.

AIMS AND OBJECTIVES: To compare liver lesion conspicuity using torso phased-array (TPA) and body coils with two pulse sequences. METHODS: Sixty patients with 125 focal hepatic lesions underwent T2-weighted fast spin-echo (T2-FSE) and fast multiplanar inversion recovery (FMPIR) imaging with a standard body coil and with a TPA coil. The first 30 patients were scanned identically in both coils with four acquisitions; the second 30 were scanned with four acquisitions in the body coil and two in the TPA coil. RESULTS: Liver-lesion contrast-to-noise (C/N) was significantly higher for the TPA coil both with four acquisitions (P< 0.001) and with two acquisitions (P < 0.002) using FMPIR, compared to with four acquisitions in the body coil. Liver-lesion C/N for T2-FSE was equivalent in both coils. Liver-lesion C/N was significantly higher (P<0.01) for FMPIR than T2-FSE both in the body coil and in the TPA coil. CONCLUSION: Liver-lesion C/N was significantly higher using the TPA coil rather than the body coil. Imaging time can be reduced by decreasing the number of acquisitions with the TPA coil.

Adult↗
PubMed1997

Hepatic resection for noncolorectal, nonneuroendocrine metastases: a fifteen-year experience with ninety-six patients.

BACKGROUND: The role of liver resection for hepatic metastases from noncolorectal, nonneuroendocrine (NCNN) cancers is unknown. This study examines a large, single institutional experience of hepatic resection for NCNN metastases. METHODS: Records of 96 patients who underwent liver resection for metastatic NCNN cancer from 1980 to 1995 at a single institution were reviewed. Survival after liver resection in this cohort of patients is reported, and factors predictive of survival are analyzed. RESULTS: Resection was performed for liver metastases from genitourinary primary tumors (n = 34), soft tissue primary tumors (n = 41), and metastases from other primary cancers (n = 21). Extent of liver resection included wedge (n = 32), lobectomy (n = 44), and extended hepatic lobectomy (n = 20). No operative deaths occurred. Overall survival rate after resection at 1, 3, and 5 years was 80%, 45% and 37%, respectively (median survival, 32 months), with 12 actual 5-year survivors. There was no difference in survival according to the type of liver resection, bilateral versus unilateral disease, or resection of extrahepatic disease. Disease-free interval of less than 36 months before discovery of liver metastases, curative resection, and primary tumor group (genitourinary was greater than soft tissue, which was greater than gastrointestinal) were predictors of a significantly better survival by multivariate analysis. CONCLUSIONS: Primary tumor type, disease-free interval, and curative resection predict those patients who benefit from hepatic resection. Hepatic resection for patients with NCNN metastasis has value in carefully selected patients.

Adult↗
PubMed1997

Ninety-six five-year survivors after liver resection for metastatic colorectal cancer.

BACKGROUND: Studies have consistently confirmed the benefit of liver resection for metastatic colorectal cancer. Few reports, however, have a long enough followup or sufficient 5-year survivors to study the clinical course of patients beyond 5 years. STUDY DESIGN: From July 1985 through December 1991, 456 patients underwent liver resection for colorectal metastases. Ninety-six actual 5-year survivors (21%) were identified and their clinical course retrospectively reviewed. RESULTS: Five-year survivors (n = 96) were more likely to have a Duke's B primary colorectal carcinoma, fewer than four metastatic lesions, unilobar disease, and a negative histologic margin when compared with patients not surviving 5 years (n = 298). Forty-four (46%) of the 96 five-year survivors had a recurrence after hepatectomy. Of these 44, 19 (43%) were rendered disease free after further treatment. Overall, 71 of the 96 five-year survivors were free of disease at last followup. The actuarial 10-year survival of this group was 78%. CONCLUSIONS: Patients that are disease free 5 years after liver resection are likely to have been cured by liver resection. Patients should be aggressively followed for recurrence because of the potential for further treatment and longterm survival.

Adult↗
PubMed1997

Liver resection for colorectal metastases.

PURPOSE: More than 50,000 patients in the United States will present each year with liver metastases from colorectal cancers. The current study was performed to determine if liver resection for colorectal metastases is safe and effective and to evaluate predictors of outcome. MATERIALS AND METHODS: Data for 456 consecutive resections performed between July 1985 and December 1991 in a tertiary referral center were analyzed. RESULTS: The perioperative mortality rate was 2.8%, with a mortality rate of 4.6% for resections that involved a lobectomy or more. The median hospital stay was 12 days and only 9% of patients were admitted to the intensive care unit. The 5-year survival rate is 38%, with a median survival duration of 46 months. By univariate analysis, nodal status of the primary lesion, short disease-free interval before detection of liver metastases, carcinoembryonic antigen (CEA) level greater than 200 ng/mL, multiple liver tumors, extrahepatic disease, large tumors, or positive resection margin was predictive of poorer outcome. Sex, age greater than 70 years, site of primary tumor, or perioperative transfusion was not predictive of outcome. By multivariate analysis, positive margin, size greater than 10 cm, disease-free interval less than 12 months, multiple tumors, and extrahepatic disease were independent predictors of poorer outcome. Short disease-free interval or multiple tumors were nevertheless associated with a 5-year survival rate greater than 24%. CONCLUSION: Liver resection for colorectal metastases is safe and effective therapy and currently represents the only potentially curative therapy for metastatic colorectal cancer. The only absolute contraindication to resection is extrahepatic disease. A randomized trial to examine efficacy of surgical resection cannot ethically be performed. Liver resection should be considered standard therapy for all fit patients with colorectal metastases isolated to the liver.

Adult↗
PubMed1997

Cholangiocarcinoma at the hepatic hilus: sonographic findings.

OBJECTIVE: This study was performed to characterize sonographic findings in patients with cholangiocarcinoma at the hepatic hilus and to compare those sonographic findings with surgical and pathologic findings. MATERIALS AND METHODS: Thirty-nine consecutive patients with hilar cholangiocarcinoma (Klatskin tumor) had preoperative color and spectral Doppler sonography and had surgical-pathologic correlation. Biliary drainage catheters were present in 24 patients (62%). In all patients, we evaluated presence of bile duct mass, level of bile duct involvement, patency of portal veins, and hepatic mass lesions. RESULTS: Ductal masses were revealed by sonography in 34 patients (87%). Masses were isoechoic in 22 patients (65%), hypoechoic in seven (21%), and hyperechoic in five (15%). The masses included nodular mural thickening in 19 patients (56%), infiltrative lesions in nine (26%), and intraductal polypoid masses in six (18%). The extent of bile duct involvement was revealed sonographically in 34 cases (87%) by the distribution of bile duct obstruction, the location of a ductal mass, or both. Portal vein involvement by tumor was shown sonographically in 20 patients (51%); 13 patients had occluded portal veins, and seven had encased portal veins without occlusion. Twenty-one portal veins in 16 patients were found to be involved at surgery; sonography showed 18 (86%) of 21 involved portal veins. Hepatic masses were present at surgery in six patients; four of these masses were malignant and two were benign. Sonography revealed five of the six masses and failed to reveal metastases in one patient who had pneumobilia from a biliary drainage catheter. CONCLUSION: Although Klatskin tumors are usually isoechoic, they can be revealed by sonography, and their morphology can be characterized. The extent of bile duct involvement may be shown on sonograms by the location of tumor and the distribution of bile duct obstruction. Portal vein involvement is frequent, and hepatic metastases are uncommon.

Aged↗
PubMed1997

Liver resection in the elderly.

BACKGROUND: The operative mortality rate for hepatic resection in the elderly has been reported to be as high as 40 per cent for extended resection. METHODS: An increasing need to justify use of limited healthcare resources prompted a prospective assessment of 133 consecutive hepatic resections performed in 30 months in patients over 65 years of age. RESULTS: The overall mortality rate was 4 per cent. Mean(s.e.m.) hospital stay was 13(1) days, and admission to the intensive care unit was required for only eight patients. By univariate analysis, male sex (P = 0.003), preoperative jaundice (P = 0.01), abnormal preoperative electrocardiogram (P = 0.05) and poor American Society of Anesthesiologists (ASA) physical status classification (P = 0.01) were predictors of cardiopulmonary complications. In a multivariate analysis only male sex and ASA classification predicted complications (P = 0.05). The 1-, 2- and 3-year survival rates for the entire group were 78, 66 and 50 per cent respectively. All survivors returned to good functional status (mean(s.e.m.) peak postoperative Karnofsky score 95(1)). When outcome was compared with that in 244 patients younger than 65 years of age who had liver resection during the same interval, the only difference was a longer mean hospital stay for the older patients: mean(s.d.) 13.4(0.5) versus 11.9(0.4) days for those aged less than 65 years (P = 0.02). CONCLUSION: Major hepatic resection can be performed in patients over 65 years old with acceptable morbidity and mortality rates.

Aged↗
PubMed1996

Rapid production of interleukin-2-secreting tumor cells by herpes simplex virus-mediated gene transfer: implications for autologous vaccine production.

Production of autologous tumor vaccines would be facilitated by the development of a rapid and efficient method for the transfer of genes into freshly isolated cells. To evaluate the potential of replication defective herpes simplex viral (HSV) amplicon vectors as gene transfer vehicles for tumor vaccine generation, a vector that expresses the human interleukin-2 (IL-2) gene (HSV-IL2) and one that expresses Escherichia coli beta-galactosidase (HSVlac) were tested in hepatoma cells of both murine and human origin. Gene transfer into murine hepatoma cells (HEPA 1-6) was both rapid and highly efficient: greater than 50% of cells expressed beta-Gal when infected at a multiplicity of infection (m.o.i.) of 1 with an exposure period of 20 min. Moreover, gene transfer was as efficient in tumor cells after irradiation with 10,000 rads as in nonirradiated tumor cells. Irradiated HEPA 1-6 cells infected with HSV-IL2 for 20 min secreted IL-2 at a rate of 1,200 +/- 160 ng/10(6) cells per day. C57B1/6J mice immunized with irradiated, HSV-IL-2-transduced tumor cells produced in this way demonstrated specific tumor immunity by in vitro splenocyte tumoricidal activity and by in vivo protection against tumor challenge. Human hepatobiliary tumor specimens harvested at the time of operation, irradiated, and infected with HSV-IL-2 also produced nanogram quantities of IL-2/10(6) cells per 24 hr. These results indicate that the HSV amplicon vector is a good candidate vehicle for gene transfer in the production of autologous tumor vaccines. By allowing rapid gene transfer to freshly harvested tumor specimens, these vectors bypass the requirement for cell culture and make feasible reinfusion of genetically modified and irradiated autologous cells within hours of tumor harvest.

Animals↗
PubMed1996

Loss of heterozygosity on the long arm of chromosome 11 in nasopharyngeal carcinoma.

Loss of heterozygosity (LOH) on the long arm of chromosome 11 had been reported in many types of solid tumors. In this study, we investigated the LOH patterns of chromosome 11 on 52 primary nasopharyngeal carcinomas using 10 microsatellite polymorphic markers. The results revealed that 28 of the 52 cases (53.8%) demonstrated LOH on at least one of the nine 11q microsatellite loci studied. The highest frequencies of LOH were found at the two loci D11S2000 (36.1%) and D11S934 (34.5 %), both located at 11q22-24. Two distinct regions of deletion were found at 11q, with the first one defined by INT-2 and D11S900 at 11q13.3-22, and the second region located between D11S2000 and D11S934 at 11q22-24. The two deletion regions overlap with the common areas of deletion reported in other tumor types. This suggests the presence of multiple putative tumor suppressor genes on chromosome 11q that may play a role in the development of nasopharyngeal carcinomas.

Aneuploidy↗
PubMed1996

Factors influencing hepatocyte trafficking during allogeneic hepatocyte transplantation: improved liver sequestration with isolated perfusion.

Transplantation of normal or ex vivo modified hepatocytes holds promise in therapy of a variety of diseases. In order to investigate hepatocyte trafficking, and specifically to determine whether the route, method of delivery, or other host factors may affect hepatocyte sequestration in the liver, 51chromium- and 111indium-labeled hepatocytes were transplanted into allogeneic hosts. Systemic injection of hepatocytes into the femoral vein resulted in sequestration mainly in the lungs (30 +/- 4%) whereas sequestration in the liver amounted to only 5 +/- 1%. Portal injection resulted in a dramatic increase in the liver sequestration (52 +/- 4%) and a reduction in the lung (2 +/- 1%, P < 0.05 vs systemic injection). Nevertheless, nearly half of portally injected hepatocytes came to rest in other organ sites. Partial hepatectomy prior to transplantation did not change the total hepatocyte sequestration in the liver or the organ specific activity. A remote site of inflammation, in the form of a turpentine abscess, also did not alter the pattern of hepatocyte trafficking. Isolated perfusion of the liver with labeled hepatocyte, however, significantly increased the sequestration of hepatocytes at this organ (control, 52 +/- 4%; isolated perfusion, 71 +/- 9%; P < 0.05). In the delivery of potentially toxic gene products for therapy, isolated perfusion of the target organ appears to provide the greatest likelihood of restricting expression of potentially toxic gene products to the target organ.

Animals↗
PubMed1996

Complete resection of the caudate lobe of the liver: technique and results.

The caudate lobe of the liver is a frequent site of involvement by metastatic or primary liver tumours. This study describes the surgical anatomy and analyses the operative technique, results and postoperative morbidity of complete caudate lobectomy. The data represent a retrospective review of 21 consecutive complete caudate lobe resections performed over a 30-month period. The most common diagnosis was metastatic colorectal cancer (nine patients) and the most common procedure was extended left hepatic lobectomy with en bloc caudate lobectomy. Four patients underwent isolated complete caudate lobe resection. The median operating time was 5 h and the median blood loss was 1160 ml. The major complication rate was 38 per cent (nine major complications in eight patients) with 10 per cent mortality rate (two deaths). The median hospital stay was 11 days. This series demonstrates the feasibility of routine complete caudate lobe resection for tumours with general principles of liver resection. Isolated caudate lobectomy can be performed safely and the addition of caudate lobectomy to major liver resection does not add significantly to the morbidity or mortality of the procedure.

Adult↗
PubMed1996

Outcome of treatment for distal bile duct cancer.

All patients with distal bile duct tumours over a 10-year period (October 1983 to December 1993) were identified by means of a prospective database. The medical records of 104 patients were reviewed. Univariate and multivariate analysis for predictors of outcome was performed. Median age of the patients was 65 (range 30-89) years. Patients presented with a clinical picture indistinguishable from that of pancreatic ductal adenocarcinoma. Twenty patients had no surgical treatment and 23 had a diagnostic laparotomy only. Biliary bypass was performed in 16 patients and radical resection was performed in 45 (pancreaticoduodenectomy, 39; bile duct excision, six). Operative mortality occurred in two of 45 patients having radical resection and complications in 17. Resection provided significant survival benefit. By univariate and multivariate analysis, resectability and negative node status (P < 0.001) were the only predictors of favourable outcome. Sex, age, preoperative stenting, grade of tumour and bilirubin level did not predict outcome. The 5-year survival rate for radically resected, node-negative tumours was 54 per cent. Surgical resection is effective therapy for distal bile duct tumours. These patients have a better outlook than those having resection of pancreatic adenocarcinoma.

Adenocarcinoma↗
PubMed1996

Interferon gamma protects against hepatic tumor growth in rats by increasing Kupffer cell tumoricidal activity.

An increasing number of hepatic resections are being performed as potentially curative surgery for malignant liver neoplasms. Hepatectomy and subsequent liver regeneration produce a local environment that enhances growth of microscopic residual tumor. To determine if pretreatment with murine interferon gamma (IFN-gamma) can protect against such enhanced tumor growth, Buffalo rats were randomized to receive a 3-day treatment of IFN-gamma (50,000 U/qD intraperitoneally) or saline. Groups then underwent intrasplenic injection of 10(6) Morris hepatoma cells, followed 1 hour later by sham (control) or partial hepatectomy (PH) of 70%. PH significantly enhanced tumor growth within the liver (control, 8 +/- 3 nodules per liver; PH, 73 +/- 12 nodules per liver; P < .001). This enhancement was attenuated by prior administration of IFN-gamma IFN-gamma/PH, 16 +/- 3; P < .001 vs. PH). Growth factor release and liver regeneration were not affected significantly by pretreatment with IFN-gamma. The effect of IFN-gamma on tumor growth is associated with a significant enhancement of Kupffer cell (KC)-mediated tumoricidal activity (percentage of specific lysis, 55 +/- 10% control, 78 +/- 11% IFN-gamma, P < .01) but not lymphocyte-mediated tumoricidal activity. Because microscopic residual disease may be present after hepatectomies for cancer, IFN-gamma may be useful agent in retarding growth of residual tumors.

Animals↗
PubMed1996

Drainage is unnecessary after elective liver resection.

PURPOSE: A prospective, randomized trial was performed to determine if intra-abdominal drainage catheters are necessary after elective liver resection. PATIENTS AND METHODS: Between April 1992 and April 1994, 120 patients subjected to liver resection, stratified by extent of resection and by surgeon, were randomized to receive or not receive operative closed-suction drainage. Operative blood loss was not an exclusion criteria, and no patient who consented to the study was excluded. RESULTS: Eighty-seven patients (73%) had resection of one hepatic lobe or more (27 lobectomies, 54 trisegmentectomies, and 6 bilobar atypical resections) and 33 had less than a lobectomy (8 wedge resections or enucleations, 9 segmentectomies, and 16 bisegmentectomies). Eighty-four patients (70%) had metastatic cancer and 36 patients (30%) had primary liver pathology. There were no differences in outcome, including length of hospital stay (no drain, 13.4 +/- 0.9 days; drain, 13.1 +/- 0.8 days; P = not significant [NS]), mortality (no drain, 3.3%; drain, 3.3%), complication rate (no drain, 43%; drain, 48%; P = NS), or requirement for subsequent percutaneous drainage (no drain, 18%; drain, 8%; P = NS). All infected collections (n = 3) occurred in operatively drained patients. Two other complications were directly related to the operatively placed drains. One patient developed a subcutaneous abscess at the drain site, and a second developed a subcutaneous drain tract tumor recurrence as the only current site of recurrence. CONCLUSION: In the first 50 consecutive resections performed since the conclusion of this trial, only 4 patients (8%) have required subsequent percutaneous drainage. We conclude that abdominal drainage is unnecessary after elective liver resection.

Abdomen↗
PubMed1996

Long range-inverse PCR (LR-IPCR): extending the useful range of inverse PCR.

The inverse PCR technique (IPCR) has proven to be very useful for the amplification of uncharacterized stretches of DNA upstream or downstream of regions that have already been cloned and sequenced. In practice, however, chromosome walking using standard IPCR is often a slow, repetitive process because only small DNA fragments are effectively amplified. The development of long and accurate PCR methodology has greatly expanded the range of DNA fragment sizes that is amenable to amplification by conventional PCR. We reasoned that combining long range PCR with IPCR would also extend the useful range of the IPCR technique. In this paper we demonstrate the utility of the hybrid, long range-inverse PCR (LR-IPCR) technique by generating clones containing long stretches of DNA flanking endogenous chicken proviral elements.

Animals↗
PubMed1996

Long-term results after resection for gallbladder cancer. Implications for staging and management.

BACKGROUND: The surgical management of gallbladder cancer is controversial. There is no consensus among surgeons as to the indications for reoperation or radical resection. OBJECTIVE: The purpose of this study was to examine results of reoperation after an incidental finding of gallbladder cancer after cholecystectomy, and results of radical resection in patients with advanced disease. METHODS: A retrospective review of 149 patients with the diagnosis of gallbladder cancer treated from 1985 to 1993 was performed. Fifty-eight patients were explored and 23 underwent resection for cure. Resection included trisegmentectomy in nine patients and bile duct resection in ten patients. Seventeen patients underwent re-exploration after an incidental finding of gallbladder cancer at initial cholecystectomy. RESULTS: Surgical resection is associated with an actuarial 51% 5-year disease-free survival rate, with a median follow-up time of 48 months. Eight patients are alive beyond 50 months. There were no operative deaths; the perioperative morbidity rate was 26%. Nodal status is the most powerful predictor of outcome. Two patients with T4, NO disease are alive without evidence of disease beyond 4 years. Thirteen of the 17 patients (76%) undergoing reoperation after simple cholecystectomy for T2 or T3 tumors had residual disease. CONCLUSIONS: Patients with nodal metastasis beyond the pericholedochal nodes should not be considered for curative resection. Tumors staged T4, NO should be included with stage III disease, and resection should be considered. Re-resection of T2 or T3 tumors after simple cholecystectomy is likely to include residual disease and should thus provide the only chance for long-term survival.

Actuarial Analysis↗
PubMed1996

Portal vein evaluation with US: comparison to angiography combined with CT arterial portography.

PURPOSE: To compare ultrasound (US) to angiography combined with computed tomography during arterial portography (CTAP) in the preoperative evaluation of the portal vein. MATERIALS AND METHODS: Sixty-three consecutive patients being considered for hepatic resection underwent color and spectral Doppler US and angiography with CTAP before surgery. The main, right, and left portal veins were evaluated separately. A total of 187 veins were assessed for encasement, occlusion, or thrombosis. RESULTS: At surgery, 41 portal veins were abnormal. US allowed detection of 38 of 41 (93%) involved portal veins with 93% sensitivity, 99% specificity, 97% positive predictive value, and 98% negative predictive value. Angiography with CTAP allowed diagnosis of 37 of 41 (90%) involved portal veins with 90% sensitivity, 99% specificity, 95% positive predictive value, and 97% negative predictive value. CONCLUSION: US is comparable to angiography combined with CTAP in evaluation of the portal vein.

Constriction, Pathologic↗