Anti-allergic and anti-inflammatory triterpenes from the herb of Prunella vulgaris

The activity-guided fractionation of the extract of the herb of Prunella vulgaris (Labiatae) led to the isolation of four triterpenes, i.e., betulinic acid, ursolic acid, 2 alpha,3 alpha-dihydroxyurs-12-en-28-oic acid, and 2 alpha-hydroxyursolic acid. One of these compounds, 2 alpha,3 alpha-dihydroxyursolic acid, demonstrated significant inhibition on the release of beta-hexosaminidase from the cultured RBL-2H3 cells in a dose-dependent manner; the IC50 value was calculated to be 57 microM. When the isolated compounds were tested for their effects on the production of nitric oxide from cultured murine macrophages, RAW 264.7 cells, ursolic acid and 2 alpha-hydroxyursolic acid exhibited strong inhibitory activities (IC50 values, 17 and 27 microM, respectively).

Gene therapy of hepatocellular carcinoma in vitro and in vivo in nude mice by adenoviral transfer of the Escherichia coli purine nucleoside phosphorylase gene

Expression of viral or bacterial enzymes in tumor cells to convert nontoxic prodrugs into highly toxic metabolites is an attractive gene-therapeutic approach for the treatment of hepatocellular carcinoma (HCC). The Escherichia coli purine nucleoside phosphorylase (PNP) converts purine analogs into freely diffusible metabolites, which are highly toxic to dividing and nondividing cells. We investigated the antitumor effects of PNP in the human HCC cell lines, HepG2, Hep3B, and HuH-7, and performed a comparison with herpes simplex thymidine kinase (TK). The genes for PNP, TK, and enhanced green fluorescent protein (EGFP) were delivered to HCC cells by identical adenoviral vectors. Fludarabine and ganciclovir (GCV) served as prodrugs for PNP and TK, respectively. Expression of PNP highly sensitized HCC cells to fludarabine treatment. Fludarabine concentrations between 0.5 and 1 microg/mL killed 100% of the cells expressing PNP with no detectable toxicity in control cells expressing EGFP. Expression of PNP in as few as 10% of HCC cells induced efficient killing of most bystander cells. Expression of TK followed by GCV treatment produced a potent growth inhibition but failed to kill all TK-expressing HCC cells. More importantly, the TK system exhibited a lower degree of bystander effect. Adenoviral delivery of PNP followed by fludarabine administration prevented subcutaneous and intrahepatic tumor formation in nude mice and was also effective for the treatment of established tumors. These results demonstrate the potential of the PNP/fludarabine system for the treatment of HCC.

A distinct tumor suppressor gene locus on chromosome 15q21.1 in sporadic form of colorectal cancer

The SM1311 family is an Ashkenazi family with dominantly inherited predisposition to colorectal adenomas and carcinomas and has a high-penetrance locus in chromosome 15q, with a multipoint logarithm of the odds score of 3.06 at marker D15S118. In the present study, we performed a high-density loss of heterozygosity study with 13 polymorphic microsatellite markers, including D15S118, spanning 15q15.3-q22.1, on 70 cases of the sporadic form of colorectal tumors. Our deletion mapping data showed a locus at D15S968 in chromosomal sub-band 15q21.1 may harbor a tumor suppressor gene in an area <0.521 Mb in physical map distance defined by markers D15S514 and D15S222. THBS1, 0.185 Mb proximal to D15S968, is the nearest known gene to this specific narrow loss of heterozygosity region. Thus, we speculate that THBS1 might be the most probable candidate gene involved in colorectal cancer carcinogenesis.

Cystic lung disease: a comparison of cystic size, as seen on expiratory and inspiratory HRCT scans

OBJECTIVE

To determine the effects of respiration on the size of lung cysts by comparing inspiratory and expiratory high-resolution CT (HRCT) scans.

MATERIALS AND METHODS

The authors evaluated the size of cystic lesions, as seen on paired inspiratory and expiratory HRCT scans, in 54 patients with Langerhans cell histiocytosis (n = 3), pulmonary lymphangiomyomatosis (n = 4), confluent centrilobular emphysema (n = 9), paraseptal emphysema and bullae (n = 16), cystic bronchiectasis (n = 13), and honeycombing (n = 9). Using paired inspiratory and expiratory HRCT scans obtained at the corresponding anatomic level, a total of 270 cystic lesions were selected simultaneously on the basis of five lesions per lung disease. Changes in lung cyst size observed during respiration were assessed by two radiologists. In a limited number of cases (n = 11), pathologic specimens were obtained by open lung biopsy or lobectomy.

RESULTS

All cystic lesions in patients with Langerhans cell histiocytosis, lymphangiomyomatosis, cystic bronchiectasis, honeycombing, and confluent centrilobular emphysema became smaller on expiration, but in two cases of paraseptal emphysema and bullae there was no change.

CONCLUSION

In cases in which expiratory CT scans indicate that cysts have become smaller, cystic lesions may communicate with the airways. To determine whether, for cysts and cystic lesions, this connection does in fact exist, paired inspiratory and expiratory HRCT scans are necessary.

Effects of flavonoids on the growth and cell cycle of cancer cells

In this study, we investigated the cytotoxicities of flavone (F01), 3-hydroxyflavone (F02), 6- hydroxyflavone (F03), 7-hydroxyflavone (F04), 3,6-dihydroxyflavone (F05), 5,7-dihydroxyflavone (F06) and 5,6,7-trihydroxyflavone (F07) to human cancer cells including P- glycoprotein (Pgp)-expressing HCT15 cells and its multidrug resistant subline, HCT15/CL02 cells. We also examined the effects of those flavonoids on the cell cycle of these cancer cells. HCT15/CL02 cells did not reveal resistance to all the flavonoids tested in comparison with HCT15 cells. In cell cycle analysis, all the flavonoids tested, except F01 and F04, reduced the G0/G1 population of SF295 cells at growth inhibitory concentrations, and increased G2/M (F02, F03 and F06) or S (F05 and F07) populations. In addition, F02 and F03 decreased the G2/M and G0/G1 population, and increased the S and G2/M population in HCT15 cells, respectively. Meanwhile, in HCT15/CL02 cells, F02 and F03 decreased the G0/G1 populations and increased the S population. In conclusion, we deemed that the flavonoids tested had diverse cytotoxic mechanisms, and exerted their cell growth inhibitory or killing activity by distinctive ways in different cells.

The Wilms tumor suppressor WT1 encodes a transcriptional activator of amphiregulin

WT1 encodes a zinc finger transcription factor implicated in kidney differentiation and tumorigenesis. In reporter assays, WT1 represses transcription from GC- and TC-rich promoters, but its physiological targets remain uncertain. We used hybridization to high-density oligonucleotide arrays to search for native genes whose expression is altered following inducible expression of WT1. The major target of WT1 was amphiregulin, a member of the epidermal growth factor family. The WT1(-KTS) isoform binds directly to the amphiregulin promoter, resulting in potent transcriptional activation. The in vivo expression profile of amphiregulin during fetal kidney development mirrors the highly specific pattern of WT1 itself, and recombinant Amphiregulin stimulates epithelial branching in organ cultures of embryonic mouse kidney. These observations suggest a model for WT1 as a transcriptional regulator during kidney differentiation.

P-glycoprotein (Pgp) does not affect the cytotoxicity of flavonoids from Sophora flavescens, which also have no effects on Pgp action

Sophoraflavanone, kurarinone (GS08), norkurarinol (GS11), kurarinol (GS12) and kushenol K are cytotoxic flavonoids isolated from Sophora flavescens. In this study, we tested the cytotoxicity of those flavonoids to human cancer cells including P-glycoprotein (Pgp)-expressing HCT15 cells and its multidrug resistant subline, HCT15/CL02 cells. HCT15/CL02 cells revealed resistance to GS08, GS11 and GS12 about 2 fold in comparison with HCT15 cells. Nonetheless, verapamil, a Pgp inhibitor, could not increase the cytotoxicity of all the flavonoids tested. We also investigated that the flavonoids could modulate the Pgp action. At nontoxic concentrations, the flavonoids could not effect on the cytotoxicity of paclitaxel, a well-known Pgp-substrate. The flavonoids also had no effects on the accumulation of rhodamine 123 in all the cells tested at 10 microM. From the results, we concluded that Pgp had no effect on the cytotoxicity of the flavonoids, and the flavonoids also had no effect on the action of Pgp. Our results also suggested that HCT15/CL02 cells had additional mechanisms for drug resistance distinct from Pgp overexpression.

Development of a serum-free medium for the production of erythropoietin by suspension culture of recombinant Chinese hamster ovary cells using a statistical design

In order to develop a serum-free (SF) medium for the production of erythropoietin (EPO) by suspension culture of recombinant Chinese hamster ovary (rCHO) cells, a statistical optimization approach based on a Plackett-Burman design was adopted. A basal medium was prepared by supplementing Iscove's modified Dulbecco's medium (IMDM) with Fe(NO3)3.9H2O, CuCl2 and ZnSO4.7H2O which are generally contained in SF medium formulations. Insulin, transferrin and ethanolamine were also supplemented to the basal medium to determine their optimal concentrations. From this statistical analysis, glutamate, serine, methionine, phosphatidylcholine, hydrocortisone and pluronic F68 were identified as positive determinants for cell growth. The SF medium was formulated by supplementing the basal medium with components showing positive effects on cell growth in suspension culture. An EPO titer in this optimized SF medium was 79% of that in IMDM supplemented with 5% dialyzed fetal bovine serum (dFBS). Furthermore, the in vitro and in vivo biological activities of EPO produced in the SF medium were comparable to those produced in the serum-supplemented medium. Taken together, the results obtained here show that a Plackett-Burman design facilitates the development of SF media for the production of EPO by suspension culture of rCHO cells.

Human interleukin 6 gene is activated by hepatitis B virus-X protein in human hepatoma cells

Interleukin 6 (IL-6) is a pleiotropic cytokine that induces many biological activities, including some aspects of the immune reaction and inflammatory responses. In the liver, IL-6 regulates the synthesis of a broad spectrum of acute-phase proteins. IL-6 is also known to be a factor involved in the immunoregulatory perturbations in patients with chronic liver diseases (CLDs). Here, we report that IL-6 can be induced by hepatitis B virus (HBV)-X protein, as evidenced by high levels of serum IL-6 in patients with CLD with HBV infection, IL-6 productions observed in HBV-X-transfected cells, and transcriptional transactivations of the IL-6 gene by HBV-X. We determined serum levels of IL-6 in patients with chronic hepatitis B (CH-B), chronic hepatitis C (CH-C), liver cirrhosis (LC) caused by hepatitis B, and LC with hepatocellular carcinoma (HCC) caused by hepatitis B (LC+HCC). Mean serum levels of IL-6 in all CLD patients were higher than those in normal controls, and the difference was statistically significant (P < 0.05). Mean IL-6 levels of LC and LC+HCC patients were significantly higher than those of CH-B patients (P < 0.05). Because the etiological factor in all cases except CH-C (CH-B, LC, and LC+HCC) was HBV, we checked the possibility of HBV-transactivator-X activation of IL-6 promoter. Using deletion constructs of 5'-flanking regulatory regions of the IL-6 gene linked to the chloramphenicol acetyltransferase gene as a reporter, we found that the binding of nuclear factor-kappaB to a cis element is essential and sufficient for the induction of the IL-6 gene by HBV-X. We also found that HBV-X enhances the binding of two subunits of nuclear factor-kappaB (p65 and p52) to their target DNA binding sequences. These observations are relevant, in that HBV-X might play an important role in hepatic inflammation and diseases by up-regulating IL-6 production, which can eventually lead to LC and HCC.

Experience of orthotopic liver transplantation in 11 patients with liver cirrhosis from Korea: medical factors affecting outcome

Orthotopic liver transplantation (OLT) has evolved to become a standard treatment of choice for end-stage liver diseases. The present study was performed to evaluate the peri-operative medical factors affecting transplantation outcome and to determine if patients with type B viral cirrhosis were acceptable for OLT. A total of 11 patients with end-stage cirrhosis, who have received OLT in Kangnam St. Mary's Hospital since May 1993, included 8 HBV-related cases, 1 Hepatitis C Virus (HCV)-related case, and 2 non-B, non-C cases. One-year cumulative survival rate by Kaplan-Meier method was 43.7%. Factors significantly associated with 1-year survival of the recipients during pre-OLT period were performance status and modified Pugh-Child score (p=0.015 and p=0.015, respectively). Among those 4 patients who lived longer than 1 year, 3 of 4 patients with HBsAg-positive had no HBV re-infection with our protocol. These results suggest that, to improve the outcome of OLT in cirrhosis patients, transplantation should be performed in the stage when patients maintain better performance and hepatic functional reserve during the end-stage of liver cirrhosis. In addition, patients with cirrhosis caused by HBV infection may be indicated for OLT, because HBV re-infection is preventable effectively with a high-dose hepatitis B immunoglobulin protocol.

Transection and occlusion of lateral semicircular canal in guinea pigs

Audiologic and histopathologic examinations were made after occlusion of the lateral semicircular canal in eight guinea pigs. The lateral semicircular canal was drilled out, and then the canal lumens were plugged with muscle pieces. After a serial recording of auditory brain stem responses for 2 months, histologic specimens of the temporal bones were prepared in the lateral semicircular canal plane. One animal developed profound hearing loss due to suppurative labyrinthitis. The other seven animals showed no significant threshold elevation during this period. Histopathologic examination revealed that the bone defect on the lateral canal was replaced with newly formed bone; the perilymphatic and endolymphatic spaces maintained their compartmentalization; and the membranous endolymphatic canal healed to form complete blind ducts. These findings suggest that proper management of the injured semicircular canal is important for maintenance of postoperative hearing.

Nucleic acid-based antiviral and gene therapy of chronic hepatitis B infection

Persistent hepatitis B virus (HBV) infection often leads to the development of chronic hepatitis, cirrhosis and hepatocellular carcinoma. There is a need to develop new antiviral approaches for the treatment of this disease. We have explored various nucleic acid-based strategies designed to inhibit HBV replication including: the use of antisense RNA and DNA constructs, DNA-based immunization techniques to stimulate broad-based cellular immune responses with particular emphasis on the generation of cytotoxic lymphocyte (CTL) activity to viral structural proteins, hammerhead ribozymes to cleave HBV pregenomic RNA in vitro and dominant negative HBV core mutant proteins as inhibitors of nucleocapsid formation within cells. In order to optimize these antiviral effects, various novel expression vectors have been developed to deliver such DNA constructs to cells. For example, adenoviral vectors carrying genes that encode for dominant negative proteins have been employed to transfect hepatocytes in vitro and in vivo. In addition, plasmid vectors have been produced to promote expression of HBV structural genes following injection into muscle cells as a means to stimulate the host's cellular and humoral immune response in the context of histocompatibility antigen (HLA) class I and II antigen presentation. These experimental approaches may have important implications for the generation of efficient antiviral effects during chronic HBV infection.

GB virus C/hepatitis G virus infection among Korean patients with liver diseases and general population

GB virus C and hepatitis G virus (GBV-C/HGV) have been identified from the patients with acute or chronic liver diseases as possible agents of non-B, non-C hepatitis by two different groups, independently. To investigate whether GBV-C/HGV plays a role among Korean patients with liver diseases, GBV-C/HGV RNA were evaluated in 337 sera by the reverse transcription polymerase chain reaction (RT-PCR) using specific primers derived from 5'-noncoding region of GBV-C/HGV genome. GBV-C/HGV RNA was identified in 11/337 (3.3%). They consisted of 1/160 (0.6%) and 10/177 (3.3%) among the general population and patients with liver diseases, respectively (P < 0.01). Nucleotide sequences of all PCR amplicons were determined by the dideoxy chain termination method and analyzed by molecular evolutionary methods. The phylogenetic tree showed all sequences could be divided into three genotypes. These results indicate that: (1) GBV-C/HGV already exist in Korea; (2) GBV-C/HGV may play some role as an etiologic factor among the Korean patients with liver diseases; (3) GBV-C/HGV infection is rare among Korean general population; and (4) there are at least three different types of GBV-C/HGV in Korea.

Genotype distribution and comparison of the putative envelope region of hepatitis C virus from Korean patients

Comparative nucleotide sequence studies of the genomes of hepatitis C virus (HCV) revealed that there are at least 6 different genotypes of HCV. The prevalence of HCV genotypes among the patients with liver diseases in Korea was investigated using the polymerase chain reaction (PCR) for the NS5 region. In the 75 HCV RNA positive samples, two genotypes, type 1b and type 2a, were the major causative agents which accounted for 60% and 33% of infections respectively, while 7% could not be assigned a genotype by the methods used. The nucleotide sequences of cDNAs encoding the putative envelope proteins from 10 type 1b and 5 type 2a genotype samples were analyzed. Approximately 31-42% of the nucleotide sequences of type 1b samples examined differed from those of different genotypes. In the case of type 2a samples, 36-42% of the nucleotide sequences differed from those of different genotypes. The diversities of the amino acid sequences were the same or greater than those of the nucleotide sequences. Two hypervariable regions (HVR1 and HVR2) were recognized in both HCV genomes of genotypes 1b and 2a. However, the sequence divergence within the HVR2 region of genotype 2a was less than that of genotype 1b.

Predictive factors for beneficial response to interferon-alfa therapy in chronic hepatitis C

OBJECTIVES

Interferon is the only established treatment for chronic hepatitis C but the host-dependent or virus-related factors affecting the response rate to interferon therapy are not yet clear. The purpose of this study was to investigate the factors predictive of response to interferon-alfa therapy in chronic hepatitis C.

METHODS

Twenty-five consecutive patients with chronic hepatitis C were randomized to three regimens of interferon-alfa: group A (n = 7, 3 MU every day for 3 months), group B (n = 8, 3 MU every other day for 3 months) and group C (n = 10, 3 MU every other day for 6 months). We quantified serum HC RNA levels by competitive reverse transcription-polymerase chain reaction (RT-PCR) and performed HCV genotyping using type-specific primers deduced form the NS5 region of the HCV genome. We also attempted to identify which demographic, biochemical and histologic factors in addition to virus-related factors would significantly predict beneficial response to interferon by multivariate analysis.

RESULTS

Sustained responders were 8 (36.4%), nonsustained responders were 2 (9.1%) and nonresponders were 12 (54.5%) of 22 patients who had received complete therapy. The initial HCV RNA level (logarithmic transformed copy numbers per ml of serum) in sustained responders (5.75 +/- 0.39) was significantly lower than that of nonsustained responders (6.80 +/- 0.71) and nonresponders (6.70 +/- 0.52) (p < 0.05). In multivariate multiple logistic regression analysis, the serum HCV RNA level before therapy was only the independent predictor of a sustained response to interferon-alfa therapy (p = 0.001).

CONCLUSIONS

Serum HCV RNA level before therapy was the most useful predictor of a sustained response to interferon-alfa therapy for chronic hepatitis C.

Molecular typing of hepatitis C virus genome from sera and liver tissues of patients with anti-HCV positive chronic liver disease

The authors investigated the distribution of HCV genotypes in patients with various chronic liver diseases in Korea. Study population was 70 individuals, positive for second generation anti-HCV EIA, consisting of 37 cases with sporadic non-A, non-B (NANB) chronic hepatitis (CH), 12 NANB hepatocellular carcinoma, 16 post-transfusion NANB hepatitis, 4 non-B blood donors and 1 healthy family member of a patient with sporadic CH. Molecular typing was performed by RT-nested PCR with type-specific primer sets deduced from the NS-5 region of HCV. The prevalence of type II was 75.0% and type III was 25.0% in sera. In liver tissues, type II HCV was shown in 63.0%, type III HCV in 3.7% and co-infections with type II and III HCV were observed in 18.5% of 27 samples biopsied. In the sera of patients with chronic hepatitis, typing results were relatively well correlated with those in tissues (75%), but type III could not be observed. Among 12 HCC patients, type III HCV appeared only in tissues, not in sera. These results suggest that type II HCV may be the major HCV type in Korea, and co-infections with type II and-III HCV may not be rare in chronic liver diseases with HCV.

Detection of HCV RNA using reverse transcription and nested polymerase chain reaction in chronic non-A, non-B liver diseases in Korea

To investigate the interrelationship between the anti-HCV prevalence and the HCV RNA positivity in chronic non-A, non-B (NANB) liver diseases in Korea (n = 137), we performed RT-nested PCR using 4 primers in the 5'-noncoding region of HCV genome. The overall HCV RNA positive rates were 62.8%; 87.7% (57/65) of anti-HCV positive cases and 40.3% (29/72) of anti-HCV negative cases. Four patterns according to the combination of anti-HCV and HCV RNA assays could be observed; 41.6% in [anti-HCV+/HCV RNA+], 5.8% in [anti-HCV+/HCV RNA], 21.2% in [anti-HCV+/HCV RNA], and 31.4% in [anti-HCV+/HCV RNA]. Our results suggested that HCV may be still related to chronic NANB liver diseases negative for anti-HCV, and other unknown agents, so-called non-B non-C, might be accounted for patients negative for both, although a low concentration of HCV RNA, or the presence of HCV RNA or HBV DNA in liver tissue should be excluded.

Pure signet ring cell type early gastric carcinoma with extensive lymph node metastases--a case report

A 42-year old man was admitted with indigestion and left upper quadrant pain. A gastrofiberscopic examination revealed a depressed, discolored lesion (1.5 × 1.5 cm) with converging irregular radiating folds in the antral portion, suggestive of early gastric cancer (type IIc). Histologically, signet ring cell carcinoma was seen. A subtotal gastrectomy was performed and the opeartive findings showed a shallow depression in the anterior wall of the greater curvature side in the antrum and multiple perigastric lymph node enlargment. On microscopic examination, the authors observed pure signet ring cell carcinoma confined to the mucosa but with widespread lymph node metastases.