[Expression of c-myc, c-erbB-2, insulin-like growth factor II andepidermal growth factor receptor in hepatitis B, cirrhosis and hepatocellular carcinoma]

In order to get a better understanding of expressions of multiple oncogenes and their possible roles in human hepatocarcinogenesis, 379 cases of liver tissues were investigated immunohistochemically. EGF receptors were immunolocalized mainly in the sinusoidal endothelial cells. They might not take part in the development of hepatocellular carcinoma (HCC), c-myc protein was showed to be expressed in cancer cells and the hepatocytes in the so-called "large-cell dysplasia" and in ductular metaplasia (DM). Its expression was also observed in some zone II hepatocytes of hepatic accini in 21% of normal liver tissues, which indicated that c-myc expression might also be related to the proliferation of mature hepatocytes. The positivity rate of c-erbB-2 product was shown to be highest among the oncogenic genes examined in this study. The positivity was observed in small polygonal liver cells (SPLCs) and the hepatocytes were observed in SCD and in DM. The expression level of c-erbB-2 oncogene in HCC cells was higher significantly than in normal hepatocytes, but lower than in SPLCs, the hepatocytes in SCD and in DM. We suggest that c-erbB-2 gene activation may play an important role not only in HCC genesis, but also in DM. Insulin-like growth factor II (IGF II), an oncofetal hepatocellular growth factor, was immunolocalized in the cancer cells, SPLCs and the hepatocytes in SCD, which indicated that activation and hyperexpression of IGF II gene might be responsible for the prominent proliferation of SPLCs and SCD, a crucial step in malignant transformation of hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Monochromatic backlighting as a laser-fusion diagnostic

The case of an x-ray radiographed (backlit) image of a CH-shell laser-fusion target to be imploded by the Omega Upgrade laser system is studied. The goal is to obtain information on the conditions at peak compression, where the experimental constraints due to target self-emission and required spatial resolution are maximal. Particular attention is devoted to the problem of discriminating against the target self-emission. It is shown that a way to selectively image the target with radiation from a backlight source is to obtain a monochromatic image at a single spectral line emitted by the backlighter. Two experimental configurations are discussed: (a) an x-ray microscope with a flat crystal monochromator, and (b) pinhole imaging in conjunction with a curved crystal monochromator. Useful images are obtained with simple CH-shell targets and without the need for a short-pulse backlighter beam.

Analysis of unconjugated morphine, codeine, normorphine and morphine as glucuronides in small volumes of plasma from children

A sensitive method for the analysis of unconjugated morphine, codeine, normorphine and total morphine after hydrolysis of glucuronide conjugates is described. The method was applicable to 50-microliters volumes of plasma. The analytes were converted to heptafluorobutyryl (HFB) derivatives before analysis by gas chromatography-negative ion chemical ionization mass spectrometry. Morphine and codeine were quantified against their [2H3]-isotopomers. Linearity, precision and accuracy were quite acceptable (in the 10(-10)-10(-9) g range), and the absolute limits of detection were < 1 pg.

[Molecular cloning of the adherence gene cluster from uropathogenic Escherichia coli and preparation of its antisera]

A genomic library of the uropathogenic E. coli J96 was constructed by using cosmid pHC79 as cloning vector. Two positive recombination cosmids which could express the adherence characters were acquired. From both cosmids a EcoRI fragment was subcloned into the vector pACYC184 by shot-gun method. Three colonies were found which exhibited MRHA and production of P Pili. One of them, pCT10/E. coli K-12 P678-54, was about 14.6 kb and was used to prepare the antisera. After absorption with pACYC184/E. coli K-12 P678-54 for three times, the antisera were revealed specific against the adherence gene cluster of uropathogenic E. coli by the SDS-PAGE and Western blotting of the P pilus crude extracts and the hemagglutination inhibition test.

[Comparative study of the expression of IGF-2 and HBxAg in human hepatocellular carcinoma and liver cirrhosis]

60 Cases of hepatocellular carcinoma (HCC) and 47 cases of liver cirrhosis (LC) were examined with immunocytochemistry methods using antibodies against IGF-2 and HBxAg on paraffin embedded sections. 32 HCC and 37 LC were found to be positive to HBxAg, in which the positive rates of IGF-2 were 100% (32/32) and 94.6% (35/37) respectively. 28 HCC and 10 LC were found to be HBxAg negative, IGF-2 was positive in 23 HCC (82.1%) and 6 LC (60%). The positive expression rates of IGF-2 in the HBxAg positive tissues were significantly higher than those in the HBxAg negative tissues (P < 0.05). There were three types of IGF-2 distribution in HCC and LC: (1) perinucleus; (2) diffuse in cytoplasm; (3) in nucleus. Small polygonal liver cells (SPLC) were found in the liver tissue surrounding the tumor or cirrhosis, the SPLC were positive to both IGF-2 and HBxAg. The positive rates of IGF-2 in SPLC were 86.4% (38/44) in HBxAg positive group and 40.5% (15/37) in the HBxAg negative group. The above findings suggest that IGF-2 plays an important role in abnormal proliferation of HCC and SPLC. The relation of IGF-2 and HBxAg and the nature of SPLC were also discussed.

Expression of insulin-like growth factor II in hepatitis B, cirrhosis and hepatocellular carcinoma: its relationship with hepatitis B virus antigen expression

Expression of insulin-like growth factor II in two human hepatocellular carcinoma cell lines and in hepatitis B, cirrhosis and hepatocellular carcinoma in 419 cases were investigated, and its relationship with the expression of hepatitis B virus X gene was studied by means of immunohistochemical and electron microscopic techniques. The results demonstrated that hepatocellular carcinoma cells (SMMC 7721 and QGY 7703) in culture could express insulin-like growth factor II. Expression seemed to be regulated by cell density, which was suggested as the molecular basis of the contact inhibition of cell proliferation. In tissue sections, cells with high expression of insulin-like growth factor II were observed not only in hepatocellular carcinoma (93%) but also in 95% of the pericancerous liver tissues, 72% of cirrhotic livers, 64% of chronic active hepatitis and 37% of chronic persistent hepatitis. In most cases of hepatocellular carcinoma, insulin-like growth factor II was localized in the cytoplasm of the cancer cells. In the benign liver disorders, four types of cells that highly expressed insulin-like growth factor II were observed: (a) a kind of small liver cell we named the small polygonal liver cell; (b) multinuclear giant hepatocytes; (c) hepatocytes in most of hyperplastic and neoplastic nodules, small hepatocyte nodules and some of regenerative nodules; and (d) some proliferating ductular cells. Even more interestingly, insulin-like growth factor II expression was shown to be closely related to the expression of hepatitis B virus X gene product. We suggest that the activation of insulin-like growth factor II gene and its overexpression may be a crucial step in the processes of hepatitis B virus-associated hepatocarcinogenesis and that the X gene product may activate the insulin-like growth factor II gene through a transactivation mechanism. In addition, we studied the characteristics of small polygonal liver cells, and the roles they may play in the regeneration and carcinogenesis of hepatitis B virus-infected liver are discussed.

Metal chelates as reversible stains for detection of electroblotted proteins: application to protein microsequencing and immunoblotting

Coomassie brilliant blue and Ponceau red have traditionally been used to stain electroblotted proteins, since they are compatible with existing N-terminal and internal protein microsequencing as well as with immunoblotting procedures. With recent improvements in sequencing and immunoblotting technology, detection of significantly smaller amounts of protein has become necessary. Metal complexes were evaluated as alternatives to conventional stains. Electroblotted proteins were detected by blocking nonspecific sites with polyvinylpyrrolidone-40 followed by incubation in metal chelate solutions at acidic pH values. Two of the most promising metal chelate stains were the Ferrozine/ferrous complex and the ferrocyanide/ferric complex. Both stained a wide variety of proteins and peptides quantitatively. Dot blots and 1D and 2D electroblots were successfully stained using iron chelates. When these two stains were utilized in combination, they were of equivalent sensitivity to colloidal gold stain. The reversibility of the metal chelate stains was substantiated by incubating stained membranes at neutral to basic pH in the presence of 20 mM ethylenediaminetetraacetic acid to rapidly elute the complexes from the bound proteins. The chelate stains were determined to be fully compatible with immunoblotting, N-terminal, and in situ internal protein microsequencing.

Substrate- and species-specific processing enzymes for chloroplast precursor proteins

Using different precursors of chloroplast proteins and stromal extracts from both Chlamydomonas reinhardii and pea chloroplasts, we analysed the specificity of stroma-localized processing peptidases. By gel filtration of a stromal extract from isolated Chlamydomonas chloroplasts, fractions could be separated containing enzymic activities for processing the precursors of the small subunit of ribulose-1,5-bisphosphate carboxylase (pSS) and of the protein OEE1 from the photosynthetic water-splitting complex (pOEE1). The enzymes differed not only in molecular size, but also in their sensitivity to inhibitors and in their pH optima. Obviously, in the stroma of Chlamydomonas chloroplasts different peptidases exist for processing of pSS and pOEE1, the latter being converted into an intermediate-sized form, iOEE1, which was found to be further processed to mature OEE1 by a thylakoid-associated protease. To study the species-specificity of the stromal peptidases, stromal extracts from Chlamydomonas and pea chloroplasts were incubated with pSS from either of these organisms. In the heterologous combinations, the precursors were partly hydrolysed, but not to the correct size. In importation assays, pSS from pea (but also the precursor of the ribosomal protein L12 from spinach) could not enter into chloroplasts from Chlamydomonas. In contrast, the algal pSS was imported into chloroplasts from pea, although it was not processed to mature SS. Our results indicate that the importation machinery and the pSS-processing enzymes in higher plants and green algae have different specificities and that in Chlamydomonas several stromal peptidases for different precursor proteins exist.

Partial purification and properties of enzymes involved in the processing of a chloroplast import protein from Chlamydomonas reinhardii

Two stromal peptidases (SPP-1 and SPP-2) were partially purified from chloroplasts of Chlamydomonas reinhardii. They specifically processed in vitro the precursor of the small subunit of ribulose-1,5-bisphosphate carboxylase (pSS), which had been synthesized by using the cloned rbcS-2 gene of Chlamydomonas. SPP-1 shortened pSS to an intermediate-sized form (iSS), while SPP-2 cut pSS and iSS to the mature small subunit SS. N-terminal amino acid sequencing demonstrated that the reaction product obtained with SPP-2 had an N-terminus identical to natural SS, and that iSS derived from pSS by hydrolysis at the amino side of the methionine located within the transit sequence. By gel filtration, apparent molecular masses of 340 kDa and 90 kDa were determined for SPP-1 and SPP-2, respectively. The comparison of these molecular masses with the protein patterns obtained by SDS/PAGE of the partially purified enzymes suggested that at least SPP-1 was a multimeric protein. The enzymes differed also in their pH optima of about 8 (SPP-1) and 9 (SPP-2) and in their sensitivity to different inhibitors. However, both enzymes seem to be serine proteases as they were completely blocked by N-alpha-tosyl-L-lysinechloromethane or tosylphenylalaninechloromethane, respectively. Competition experiments, using either mature SS or a synthetic hexadecapeptide with 15 amino acids similar to the C-terminal end of the transit sequence of pSS, indicated that SPP-2 had some affinities not only to the transit sequence of pSS, but especially to sequences in the mature protein part. We conclude that SPP-2 in Chlamydomonas is the enzyme involved in import of pSS into chloroplasts and responsible for its processing by a one-step mechanism.

[The abnormal cytokeratin expression in HBV-caused hepatitis, early-cirrhotic and cirrhotic livers, its mechanism and significance]

An ABC immunohistochemical study of the expression of cytokeratin (CK19 and CK18) was carried out in 315 cases of HBV-caused hepatitis, early-cirrhotic and cirrhotic livers. It was shown that hepatocytes in 73% of chronic active hepatitis (CAH) (80/110) and 81% of early-cirrhotic and cirrhotic livers (117/144) expressed CK19 (the abnormal CK expression), which could be of help in differentiating CAH from chronic persistent hepatitis, subtype CAH (mild, moderate to severe type) and in determining the activity of early-cirrhotic and cirrhotic livers. The abnormal CK expression was shown to be closely related to the activity of liver disorders. The CK19 expression in hepatocytes had the closest relations with the piece-meal necrosis of hepatocytes, isolation of hepatocytes into groups by connective tissue, and fibrosis. It is suggested that CK19 expression may be one of the local reactions to the piece-meal necrosis of hepatocytes.

[Microbiological production of 3-oxo-bisnorchola-1, 4-dien-22-oic acid from cholesterol by an Arthrobacter 82]

Among nineteen strains of Arthrobacter which showed to be able to decompose cholesterol in preliminary experiments, a strain of Arthrobacter 82 was selected for microbiological production of 3-oxo-bisnorchola-1,4-dien-22-oic-acid (BNC) from cholesterol. The yield is over of 50% weight percent concentration of 0.25% in the presence of cobalt sulfate. The main intermediate in such a conversion process is cholestenone. Lower glucose and higher corn steep liquor concentration were favorable for side chain degradation of cholestenone and more BNC could be produced. BNC was crystallized in acidic solution and obtained by centrifugation. The structure and characteristics of BNC has been identified by means of conventional physical, chemical and spectrometric techniques.

Effects of dietary selenite, copper, and zinc on tissue trace mineral levels in chicks

Studies were conducted to determine whether nutritional selenium (Se) status affects the nutritional status of the chick with respect to other trace elements, particularly copper (Cu) and Zinc (Zn). Severe Se deficiency was produced in chicks by the use of diets that contained exceedingly low contents (less than 0.010 ppm) of Se, but contained adequate amounts of all other known essential nutrients. This diet was based upon corn and soybean meal produced in areas of China with endemic Se deficiency of geobotanical origin. A level of at least 0.10 ppm Se was found to be required to maintain normal Se status of chicks fed this diet, and Se deficiency resulted in decreased levels of Cu, Zn, and molybdenum in the pancreas (liver and plasma levels were not affected). High dietary supplementation of Zn nor Cu did not affect the short-term utilization of Se, as indicated by the 18-h responses of Se-dependent glutathione peroxidase in plasma and liver.

Uncomplicated selenium deficiency produced in chicks fed a corn-soy-based diet

Day-old chicks were fed a practical-type diet based on corn- and soybean meal produced in a severely Se-deficient area of northeastern China. The diet contained 0.007 ppm Se and resulted in marked decreases in the activities of Se-dependent glutathione peroxidase in plasma and pancreas within 6 days of feeding. Chicks fed this basal diet showed histological signs of acinar atrophy of the pancreas, hyaline body formation, vacuolation and cytoplasmic shrinkage by 18 days and significantly elevated activities of amylase in plasma by 30 days. Each of these changes was prevented by supplementing the basal diet with Se to bring it to a level of 0.20 ppm. Chicks fed a Se-deficient purified diet based on crystalline amino acids also showed decreased Se-dependent glutathione peroxidase activities in plasma and pancreas, pancreatic damage as evidenced by histological examination and increases in plasma amylase activities. However, these signs of nutritionally induced pancreatic atrophy occurred sooner and were of greater magnitude than those observed in Se-deficient chicks fed the practical diet within the 30-day experimental period. These results, therefore, constitute the first report of nutritionally induced pancreatic atrophy in Se-deficient chicks fed a diet containing intact protein, and we suggest that a factor(s) associated with the practical diet acts to partially protect the chicks from this pathological consequence of severe Se deficiency.