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S N Thung

Publications and source records attributed to S N Thung.

At least 19 recordsLinked to original sources
PubMed1992

The histological features of chronic hepatitis C and autoimmune chronic hepatitis: a comparative analysis.

Before the availability of serological markers for hepatitis C, the morphological features of this diagnosis, which represents most non-A, non-B hepatitis, could not be confirmed. We examined biopsy specimens from 50 patients with chronic hepatitis C and 21 patients with autoimmune chronic hepatitis. Each biopsy specimen was graded on 19 different histological features. The results indicated that at the time of biopsy, the average age of patients with chronic hepatitis C was 46 yr vs. 36 yr for autoimmune chronic hepatitis. Cirrhosis was seen more frequently in autoimmune chronic hepatitis (90%) than in hepatitis C (58%). Features more commonly observed in chronic hepatitis C were bile duct damage (91% vs. 40%), bile duct loss (91% vs. 20%), steatosis (72% vs. 19%) and lymphoid cell aggregation (follicles) within portal tracts (49% vs. 10%). Severe lobular necrosis and inflammation (76% vs. 38%), piecemeal necrosis (81% vs. 10%), multinucleated hepatocytes (29% vs. 6%) and broad areas of parenchymal collapse (76% vs. 6%) were seen more often in autoimmune chronic hepatitis. Exclusion of five patients with autoimmune chronic hepatitis who received immunosuppression before biopsy accentuated these differences. In conclusion, morphological criteria, in addition to serological data, may be useful for differentiating chronic hepatitis C from autoimmune chronic hepatitis, which histologically is a more aggressive disease.

Adult↗
PubMed1992

Macroregenerative nodules and hepatocellular carcinoma in forty-four sequential adult liver explants with cirrhosis.

Macroregenerative nodules, also called nodules of adenomatous hyperplasia, have been well documented in Japan. Extensive studies support the hypothesis that in the Japanese population these lesions represent a possible pathway for hepatocarcinogenesis. However, reporting of these lesions in non-Japanese populations has so far been rare. We examined 44 sequential cirrhotic hepatectomy specimens from adult patients who underwent orthotopic liver transplantation at our institution. All livers were serially sectioned every 0.5 cm. Macroregenerative nodules were defined as regenerative nodules at least 1 cm in diameter. Forty-eight macroregenerative nodules were found in 11 livers (25% of livers). The antecedent diseases in these livers included hepatitis C (3), alcoholism (2), primary biliary cirrhosis (2) (one with iron overload), cryptogenic cirrhosis (2), hepatitis B (1) and alpha 1-antitrypsin deficiency (1). The macroregenerative nodules often differed from the surrounding nodular parenchyma in color, texture or the degree to which they bulged beyond the cut liver surface. Three livers contained grossly apparent hepatocellular carcinomas. Microscopically, macroregenerative nodules could be classified as those with (type 2) and without (type 1) dysplasia. Four livers had type 1 lesions, two had type 2 lesions and five had lesions of both types. We found 36 type 1 lesions in all and 12 type 2 lesions, 3 containing foci of microscopic carcinoma. All hepatocellular carcinomas arose in livers containing macroregenerative nodules (either type). Liver cell dysplasia, large-cell or small-cell, was observed in cirrhotic nodules of 27 livers. Microscopic or macroscopic hepatocellular carcinoma occurred in three livers with large-cell but not small-cell dysplasia and in one liver without dysplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1992

Detection of replicative hepatitis C virus sequences in hepatocellular carcinoma.

Several serologic studies suggest that infection by hepatitis C virus (HCV) may be associated with the development of hepatocellular carcinoma (HCC). Therefore, we examined tumor tissue and/or the surrounding liver of 20 patients for viral sequences by the polymerase chain reaction (PCR). In 12 cases, liver and tumor tissues were separable for extraction. RNA was extracted from frozen tissues and used as a template for reverse transcription followed by double PCR with nested primers for the 5'-untranslated (NT) and nonstructural NS3 regions of HCV. In addition, the tissue extracts were tested by single PCR for X gene and S gene sequences of hepatitis B virus (HBV). NT region sequences of HCV were detected in the available tumor tissue of all anti-HCV-positive patients except for one. Negative (replicative) strands of HCV RNA were found in the same tissues as positive (genomic) strands at almost the same relative amounts, suggesting replication of HCV in the tumor tissue rather than contamination by HCV-positive blood. HBV X and S sequences were demonstrated in two tumors, but were absent from three tumors that were surrounded by liver tissues with HBV X sequences. One patient had nucleic acids of both viruses in tumor tissue. These observations suggest that in addition to HBV, HCV may play a role in the development of hepatocellular carcinoma.

Adolescent↗
PubMed1992

Expression of sialylated Lewis(x) antigen in chronic and neoplastic liver diseases.

Phenotypic expression of sialylated Lewis(x) antigen by means of the monoclonal antiserum SNH3 was studied in 87 livers, which included normal and steatotic livers and livers with chronic persistent and chronic active hepatitis, alcoholic hepatitis, allograft rejection, focal nodular hyperplasia, hepatocellular carcinoma, cholangiocarcinoma, metastatic carcinoma, cirrhosis of various causes (autoimmune, alcoholic, viral, drug induced, Wilson's disease, and primary biliary cirrhosis). The biotin-streptavidin-peroxidase method was used on formaldehyde-fixed, paraffin-embedded sections. Sialylated Lewis(x) antigen was not demonstrated in normal livers. Hepatocellular expression in a diffuse or perinodular honeycomb pattern was seen in cirrhosis, irrespective of cause. Sialylated Lewis(x) antigen was also observed in hepatocytes around metastatic carcinoma in the absence of inflammation, cirrhosis, or regeneration. Some bile ductules, most likely ductular hepatocytes, but not bile ducts, expressed sialylated Lewis(x) antigen. Sialylated Lewis(x) antigen was seen diffusely in fibrolamellar hepatocellular carcinoma, focally in other hepatocellular carcinomas, and either focally or diffusely in cholangiocarcinomas.

Chronic Disease↗
PubMed1992

HMB-45 reactivity in adrenal pheochromocytomas.

Melanoma-specific antibody (HMB-45) is highly specific for junctional nevi, malignant melanomas, and related lesions. Rarely have other benign or neoplastic tissues demonstrated positivity with the monoclonal antibody following purification. In the present study, four of 12 pheochromocytomas contained chief cells that reacted with HMB-45. We discuss the clinical and pathologic implications of this finding.

Adolescent↗
PubMed1992

Diminished ratio of estrogen receptors to progesterone receptors in breast carcinomas of women who have had multiple miscarriages.

We examined the relationship of a history of miscarriage to the ratio of tumor estrogen receptors to progesterone receptors in 74 women with breast carcinoma evaluated between 1988 and 1990. Only women who had been pregnant and whose tumor contained both estrogen and progesterone receptors were included. Women with breast carcinoma and a history of two to four miscarriages had significantly lower ratios (less than 1) of tumor estrogen receptors to progesterone receptors than women with a history of zero or one miscarriage (greater than 1). This finding may be the result of a genetic anomaly in breast cancer patients that also affects the uterine environment during the reproductive years.

Abortion, Habitual↗
PubMed1991

Fetal fibronectin in cervical and vaginal secretions as a predictor of preterm delivery.

BACKGROUND: Preterm delivery is the leading cause of neonatal mortality in the United States, but efforts to address the problem are hampered by the inability to predict accurately which pregnancies are at risk. We postulated that damage to the fetal membranes may release fetal fibronectin into the cervix and vagina, giving rise to a biochemical marker for preterm delivery. METHODS: We measured fetal-fibronectin concentrations in cervical and vaginal secretions, amniotic fluid, and maternal plasma with a sensitive immunoassay using the monoclonal antibody FDC-6. Immunohistochemical studies were used to determine the distribution of fetal fibronectin in the placenta and amniochorionic membranes and to ascertain its cell of origin. RESULTS: Women with uncomplicated pregnancies (n = 163) who delivered at term rarely had cervicovaginal fetal-fibronectin concentrations above 0.05 micrograms per milliliter between 21 and 37 weeks of gestation (11 of 267 cervical samples [4 percent] and 9 of 267 vaginal samples [3 percent]. High levels of fetal fibronectin were detected in amniotic fluid and in the cervical or vaginal secretions of 93.8 percent of the women with preterm rupture of membranes (n = 65). Cervical or vaginal fetal fibronectin was also present in 50.4 percent of the women with preterm uterine contractions and intact membranes (n = 117), and its presence identified the women who delivered before term (n = 60) with a sensitivity of 81.7 percent and a specificity of 82.5 percent. In the placenta and membranes, fetal fibronectin was found at points of contact with the uterine wall. CONCLUSIONS: The presence of cervicovaginal fetal fibronectin in the second and third trimesters of pregnancy identifies a subgroup of women who are at high risk for preterm delivery. This phenomenon may reflect the separation of the chorion from the decidual layer of the uterus, with the release of intact or degraded chorionic components of the extracellular matrix into the cervical and vaginal secretions.

Amniotic Fluid↗
PubMed1991

Excessive weight gain after liver transplantation.

Twenty-eight patients (19 females, 9 males) were evaluated pre- and posttransplant to determine the frequency and find predictors of excessive weight gain after orthotopic liver transplant. Posttransplant, 21 patients gained and 7 patients lost weight as compared with their pretransplant dry weight. The majority of weight gain occurred between 2 and 16 months; 64.3% of patients (18/28 pts.) became overweight. All patients overweight prior to transplant (11 pts.) were more overweight posttransplant (P less than 0.005). Overweight and nonoverweight patients were similar in age, female predominance, etiology of liver disease, hypercholesterolemia, and hypertriglyceridemia pretransplant, as well as diabetes mellitus and medications including prednisone posttransplant. Overweight patients more commonly had a family history of diabetes mellitus, arteriosclerotic heart disease, and hypertension. They also had more hypertension, hypercholesterolemia, hypertriglyceridemia, abnormal physical findings related to the liver, and abnormal results of hepatic tests posttransplant. Mean rate of weight gain for overweight patients compared with nonoverweight ones during the first 16 months after transplant was 1.5 kg/month +/- 0.9 vs 0.4 kg/month +/- 0.4 for those not overweight. After 16 months mean rate of increase was slower for overweight patients (0.3 kg/month +/- 0.3), whereas weight appeared to stabilize in the nonoverweight ones. We conclude that excessive weight gain after liver transplant is common and occurs early. Since obesity may contribute to, as well as be a separate cause, of hepatic abnormalities, confusion may result when interpreting abnormal results of hepatic tests. Obesity prior to transplant predicts excessive weight gain posttransplant, although all patients may be at risk.

Adult↗
PubMed1991

Detection of hepatitis C virus sequences in liver tissue by the polymerase chain reaction.

Although sensitive assays for serum antibodies to hepatitis C virus (HCV/anti-HCV) have been developed recently, the relation of anti-HCV to HCV infection of the liver has not been clarified. Therefore, we determined the presence of HCV RNA by the reverse transcription-polymerase chain reaction (PCR) in liver biopsy specimens of 21 patients with chronic liver disease and 5 control patients. RNA was extracted from frozen liver tissues by the guanidinium method, HCV cDNA was synthesized by reverse transcription, and core region and NS3 region sequences were amplified by PCR. The sensitivity and specificity of the reaction was significantly enhanced by double PCR with nested primers followed by Southern blotting with an HCV specific oligomer probe. NS3 region sequences were detected in the liver specimens of 12 out of 15 anti-HCV positive patients. Core region sequences were detected in 9 patients, all of whom were also positive for NS3 region sequences. HCV sequences were not detected in 11 anti-HCV negative patients. In all cases, the integrity of the extracted RNA was demonstrated by successful amplification of albumin mRNA as internal control. Our findings demonstrate the feasibility of the reverse transcription-double PCR method followed by Southern blotting for the detection of HCV sequences in liver tissues. In this system, the detection rate of NS3 region sequences is higher than that of core region sequences. There is a statistically significant correlation between high titer anti-HCV antibodies in serum and NS3 region sequences in liver tissue. However, not all anti-HCV positive patients had HCV positive hepatitis. The reverse transcription-polymerase chain reaction for HCV sequences on liver tissue extracts may reveal valuable information on the diagnosis of HCV infection and the pathogenesis of chronic hepatitis C.

Base Sequence↗
PubMed1991

Hepatocellular carcinoma in a long-term survivor of intrahepatic biliary duct hypoplasia.

We describe the development of hepatocellular carcinoma (HCC) in a 46-yr-old woman with intrahepatic biliary duct hypoplasia. Her underlying liver disease was quiescent for many years until a dramatic rise in serum bilirubin was seen. Orthotopic liver transplantation was performed, and a large tumor was found during surgery. A bile-producing HCC was identified, infiltrating about 50% of an otherwise noncirrhotic liver which had a paucity of intrahepatic ducts. The findings of HCC in this long-term survivor of intrahepatic biliary duct hypoplasia indicates HCC may occur in patients with long-standing disease.

Bile Ducts, Intrahepatic↗
PubMed1991

Human fetal hepatocytes respond to inflammatory mediators and excrete bile.

Under strict observation of the ethical guidelines of the 1975 Declaration of Helsinki Human Research Committee, primary hepatocyte cultures were prepared from second-trimester fetal liver specimens. We have shown for the first time that fetal hepatocytes have the capacity to produce an acute-phase response on treatment with inflammatory mediators. Addition of interleukin-6 to the cultures resulted in strong induction of C-reactive protein and alpha-1-antichymotrypsin expression, whereas albumin expression was repressed. In contrast to interleukin-6, transforming growth factor-beta did not induce C-reactive protein expression. However, as in adult hepatocytes, fetal cells responded to transforming growth factor-beta by reduced albumin synthesis. We were able to show by virtue of fluorescein excretion into sealed clefts that fetal hepatocytes have the functional capacity to form bile. Our findings indicate that second-trimester hepatocytes can be regarded as fairly mature liver cells.

Acetylcholine↗
PubMed1990

Oestrogen receptor B-region polymorphism and spontaneous abortion in women with breast cancer.

To examine whether a variant human oestrogen receptor gene, which differs from the wild-type gene in the B region, was associated with spontaneous abortion, obstetric histories of breast cancer patients with this variant were compared with those of breast cancer patients with the wild-type gene. In women with the B-variant, 50% of pregnancies ended in spontaneous abortion, compared with 10% for women homozygous for the wild-type gene. B-variant women also had a higher proportion of spontaneous abortions and a higher number of spontaneous abortions per woman than did those with the wild-type gene.

Abortion, Habitual↗