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Biomedical subjects

J M Ham

Publications and source records attributed to J M Ham.

At least 19 recordsLinked to original sources
PubMed1996

Higher expression of oncoproteins c-myc, c-erb B-2/neu, PCNA, and p53 in metastasizing colorectal cancer than in nonmetastasizing tumors.

BACKGROUND: Expression of individual oncogenes may predict outcome in patients with metastatic colorectal cancer (CRC). We studied the oncogene profile in the tumors of patients with CRC and assessed their value as predictors of liver metastases. METHODS: The oncoproteins c-myc, c-erbB-2/neu (c-neu), PCNA and p53, were measured by immunohistochemistry in sections of metastasizing human CRC (n = 34) and their liver secondaries as well as in sections of nonmetastasizing human CRC (n = 25). RESULTS: The metastasizing primary CRC expressed proliferating-cell nuclear antigen (PCNA), c-neu, and c-myc at significantly higher levels than the nonmetastasizing primary cancer, p53 was also overexpressed in the metastatic group compared with the nonmetastasizing CRC, but this difference was not significant. The frequency of expression of all these markers was similar in the metastasizing primary CRC and the liver secondaries from the same patients. There was no correlation between the expression of the individual markers and histological grade, DNA ploidy, and subsequent local recurrence and lung metastasis and survival. However, when both groups were assessed together, positive expression of c-myc was more likely to occur in poorly differentiated tumors, whereas PCNA expression increased with more advanced Dukes stages. CONCLUSION: These results suggest that the overexpression of c-myc, c-neu, PCNA, and p53 may occur in CRC that are likely to metastasis to the liver.

Colorectal Neoplasms↗
PubMed1996

DNA flow-cytometric analysis in colorectal cancer: a comparison of metastasizing and non-metastasizing tumours.

The most common cause of death in patients with colorectal cancer is metastatic liver disease. In order to identify patients at a high risk of developing hepatic secondaries from colorectal cancers, DNA content was measured in metastasizing colorectal primaries (Group I, n = 32) as well as in their subsequently resected liver secondaries and in sections of non-metastasizing colorectal cancers (Group II, n = 25). A modified interpretation system involving both a DNA index and percentage of cycling cells (those in S and G2 + M phases) was developed. DNA content was measured in paraffin-embedded sections by flow cytometry using internal controls (human peripheral blood mononuclear cells) and non-malignant tissue controls (19 patients with diverticular disease). In Group I there were significantly more tumours with both abnormal ploidy (aneuploid or abnormal tetraploid peak) and > 15% cycling cells compared with Group II (Chi-squared; P = 0.034). The combination of abnormal ploidy and > 15% cycling cells was superior to Dukes' classification for identifying metastasizing tumours (Logistic Regression; P = 0.047). However, it was not possible to discriminate between the two groups using either DNA ploidy or the percentage of cycling cells alone. The metastasizing colorectal cancers exhibited similar DNA ploidy characteristics and had a similar percentage of cycling cells compared with their liver metastases. These results suggest that tumour DNA ploidy plus the percentage of cycling cells may predict the development of liver metastases and thus survival in patients with colorectal cancer.

Cell Cycle↗
PubMed1993

Aortic revascularization of orthotopic liver allografts: indications and long-term follow-up.

BACKGROUND: Occasionally because of certain conditions that would imperil arterial supply to a hepatic graft, it is necessary to base the arterial supply on the aorta. METHODS: Twenty orthotopic liver transplants (OLTs) in 19 patients were performed with arterial revascularization based on the aorta (Ao-OLT). In two patients the donor celiac axis was anastomosed directly to the aorta and in 18 to a conduit anastomosed to either the supraceliac (n = 10) or infrarenal (n = 8) aorta. RESULTS: One thrombosis occurred 2 months after the placement of a supraceliac conduit in an adult patients, accounting for a cumulative 1-year hepatic artery patency rate of 91.7% +/- 8.0% for 16 grafts placed in 15 adults and 100% for four grafts placed in four children. In comparison, hepatic artery-based transplantation was associated with a 1-year patency rate of 92.6% +/- 1.9% for 245 adults and 94.7% +/- 5.1% for 19 children (difference not significant compared with Ao-OLT). By logistic regression analysis, the only factor independently associated with hepatic artery thrombosis was retransplantation (1-year hepatic artery patency rate 85.7% +/- 5.9% [n = 38] for retransplants vs 93.9% +/- 1.7% for primary transplantation [n = 246]; p < 0.05). For retransplantation, Ao-OLT revascularizations were superior to those based on the hepatic artery (1-year patency rate 100% [n = 11] vs 79.9% +/- 8.1% [n = 27]; p < 0.05). CONCLUSIONS: Indications for Ao-OLT include poor hepatic arterial inflow, small or anomalous recipient hepatic arteries, friable or attenuated native hepatic arteries as may be present during retransplantation, and recipient age less than 1 year, especially those less than 15 kg or in whom the recipient artery is less than 3 mm in diameter. In these more precarious situations, Ao-OLT achieves patency rates similar to those of primary, uncomplicated OLT, is superior for retransplantation, and has technical advantages in the small pediatric liver recipient.

Adolescent↗
PubMed1992

Resource utilization and outcome of liver transplantation for alcoholic cirrhosis. A case-control study.

Liver transplantation for alcoholic cirrhosis remains controversial at some transplantation centers. We compared resource utilization and outcome in alcoholic and nonalcoholic cirrhotic patients undergoing liver transplantation. Data were collected from 56 patients who underwent transplantation for alcohol-related cirrhosis from August 1985 to February 1991 and compared with data from a control group matched for age, sex, Child-Pugh class, and date of transplantation. No significant differences were noted in the resource utilization variables examined or in outcome (as assessed by indicators of early graft function, frequency of sepsis, incidence of rejection, renal function, and retransplantation rate). One-year survival was not significantly different (75% for the alcoholic cirrhotic group vs 76% for the nonalcoholic cirrhotic group). We conclude that liver transplantation for end-stage alcohol-related cirrhosis provides excellent results and that resource utilization appears to be equivalent to that for patients undergoing transplantation for non-alcohol-related cirrhosis.

Actuarial Analysis↗
PubMed1992

Biochemical and histopathological correlation in liver transplant: the first 180 days.

It is not known whether the histopathology of the liver allograft can be predicted from biochemical measurements in serum with the same confidence as in the native liver. To answer this question we compared the histopathological diagnoses in 170 biopsy specimens from 70 adult transplant recipients obtained during the first 180 days, with the concentrations of the serum bilirubin and the activities of AST, ALT and alkaline phosphatase measured at the same time. The most frequent diagnosis was cholestasis (n = 45), which was mild, moderate or severe and which may have been complicated by rejection (n = 28) or ischemia (n = 14). Hepatitis (n = 14), ischemia with rejection (n = 6) and spotty focal necrosis (n = 6) were diagnosed less frequently. Fifteen biopsy specimens were reported as histopathologically normal. In general, biochemical measurements discriminated poorly between different histopathological diagnoses. The histopathologically normal liver often showed an abnormal pattern of enzymes and an increase in the serum bilirubin level. As a result histopathologically normal biopsy specimens were indistinguishable biochemically from those with hepatitis. When two pathological conditions were found to coexist (e.g., cholestasis with either rejection or ischemic necrosis, or ischemic necrosis with rejection), the effect on the serum biochemistry was usually not additive and in some instances returned the biochemical abnormalities toward normal. With the exception of the serum bilirubin level, which increased with the severity of uncomplicated cholestasis, we could not identify a specific pattern of biochemical changes corresponding to a given histopathological diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Preoperative risk factor assessment in liver transplantation.

BACKGROUND: Despite the increasing success of liver transplantation, there is lack of objective data defining appropriate candidate suitability. This study was undertaken to determine preoperative risk factors that independently or in combination affected outcome after orthotopic liver transplantation. METHODS: We reviewed data on 229 consecutive adult liver transplant recipients. Thirty-one preoperative risk factors recorded at the time of listing and immediately before transplantation were analyzed. Outcome variables included hospital mortality rates, bacterial or fungal sepsis, and the need for renal support. RESULTS: The overall hospital mortality rate was 15.7%. Patients who were in the intensive care unit immediately before transplantation had the highest hospital mortality rate (32.6%; p = 0.006), incidence of bacterial sepsis (51%; p = 0.001), fungal infection rate (27.6%; p = 0.001), and need for renal support (38.7%; p = 0.001). Preoperative renal dysfunction was significantly associated with sepsis and was reflected in higher hospital mortality rates (29.5%; p = 0.011). Child-Pugh class C was associated with higher mortality rates (23.9%; p = 0.017), an increased incidence of bacterial (37.2%; p = 0.020) and fungal infection (20.3%; p = 0.049), and a 30.4% requirement for postoperative renal support (p = 0.004). CONCLUSIONS: These results emphasize the need for earlier referral and transplantation in patients with advanced liver disease. Further studies are needed to refine identified risk profiles and devise strategies to decrease morbidity and mortality rates.

Adult↗
PubMed1991

Chemotactic cytokine (IL-8 and MCP-1) gene expression by human whole blood.

The salient features of systemic or local inflammation are the myriad of cellular and humoral interactions that result in elicitation of inflammatory leukocytes. In this study using specialized connective tissue, intact whole blood, we demonstrate the gene expression of two novel chemotactic factors. The buffy-coat cellular expression of neutrophil chemotactic/activating factor/interleukin 8 (IL-8) and monocyte chemotactic/activating protein (MCP-1) mRNA were time and dose-dependent in response to either lipopolysaccharide or zymosan stimulation. This system with the complexity of tissue provides a unique model for the determination of chemotactic cytokine gene expression.

Antigens↗
PubMed1991

Liver transplant for fulminant hepatic failure.

Fulminant hepatic failure is a challenging indication for liver transplantation because of associated multiple organ failure, profound neurologic abnormalities and coagulopathy. Sixteen patients have undergone emergent orthotopic liver transplantation for this indication at the University of Michigan, Ann Arbor, Michigan. Despite the associated problems, patient survival (68.2% at 2 years), intra-operative blood product utilization and duration of surgery were comparable to patients receiving liver transplants for other indications. All patients experienced complete recovery from preoperative neurologic abnormalities. Recurrent viral hepatitis did occur but did not result in allograft loss. For selected patients, orthotopic liver transplantation is excellent therapy for patients presenting with fulminant hepatic failure.

Adolescent↗
PubMed1991

Obesity and renal transplantation.

In this study, we examined the influence of pre-existing obesity (weight more than 120 per cent of ideal body weight) on outcome after renal transplantation. Among 263 cyclosporine-treated recipients of renal allografts, 223 (85 per cent) were nonobese and 40 (15 per cent) were obese prior to transplantation. Obese and nonobese recipients were similar with regard to age, sex, renal diagnosis, history of prior transplant, donor source, pretransplant blood pressure, pretransplant antihypertensive agents, diabetic recipients with insulin requirements more than 40 units per day and pretransplant serum cholesterol. Duration of hospitalization was similar (26 +/- 25 versus 25 +/- 14 days; p = NS). There was a significantly higher incidence of wound infections in obese recipients (17.5 versus 6.3 per cent; p = 0.036); other complications occurred with similar incidence. Preoperative per cent of ideal body weight correlated with post-transplant weight gain during the first post-transplant year (p = 0.00002). After one year, obese recipients had gained 14.2 +/- 2.2 kilograms compared with 8.9 +/- 0.6 kilograms for nonobese patients (p = 0.002). Mean doses of prednisone, azathioprine and cyclosporine were similar at three, six and 12 months post-transplant. There were no differences in blood cyclosporine, serum cholesterol or blood glucose levels at any time. Blood pressure measurements were similar throughout the first post-transplant year. There was no difference in the incidence or number of rejection episodes. Actuarial patient survival rate for nonobese patients was 93 per cent at three years. For obese patients, three year actuarial patient survival rate was 90.5 per cent (p = NS). Actuarial graft survival rate among nonobese patients was 71.8 per cent at three years. For obese patients, three year actuarial graft survival rate was 64.5 per cent (p = NS). In conclusion, obese patients with end stage renal disease are good candidates for renal transplantation. Obesity does not seem to constitute a major risk factor, the most notable adverse outcomes being an increased incidence of wound infection and continued weight gain through the first post-transplant year.

Actuarial Analysis↗
PubMed1990

Tumor necrosis factor-alpha gene expression in human whole blood.

Tumor necrosis factor-alpha (TNF) is recognized as a principal mediator of a variety of pathophysiologic and immunologic events. Lipopolysaccharide (LPS) challenge, either in vitro or in vivo, results in significant TNF production. In this study we present data demonstrating LPS-induced TNF mRNA expression and bioactivity using an in vitro tissue system of whole blood (WB). The kinetics of LPS-induced TNF production by WB was significantly accelerated as compared to isolated cultured peripheral blood monocytes (PBM). At post-LPS challenge, plasma from WB demonstrated a rapid rise in TNF bioactivity, peaking by 4 hr (1,021 units/ml/10(6) cells), plateauing between 4 and 8 hr, and then decreasing over the next 16 hr. In contrast, the highest measured TNF bioactivity from PBM did not occur until the 24-hr time-point (175 units/ml/10(6) cells). Whole blood buffy-coat TNF mRNA was assessed by Northern blot analysis, and demonstrated significant TNF mRNA accumulation at 1 hr and a peak 2 hr post-LPS challenge. By 8 hr TNF mRNA was undetectable. Concomitant administration of LPS with either prostaglandin E2 (10(-6)M) or Dexamethasone (10(-6)M) resulted in significant suppression of LPS-induced TNF production. This data supports WB as a useful in vitro medium for the molecular and cellular analysis of TNF. As specialized connective tissue, WB may provide an important environment to study the pharmacologic manipulation of TNF mRNA and bioactivity.

Blood Physiological Phenomena↗