[Contents of ten trace elements in Epimedium acuminatum Franch. and its different processed products]

OBJECTIVE

Determine and compare the contents of ten trace elements in crude E. acuminatum and its three different processed products.

METHOD

Using flame atomic absorption spectrometry.

RESULT

The ten trace elements were found in both the crude drug and its three processed products, and in terms of contents some of the trace elements in all the three processed products are higher than those in the crude drug.

CONCLUSION

According to the trace element contents, the three processed products of E. acuminatum have their own advantages. It is thus suggested that thoroughgoing clinical and experimental researches be performed anew for the long-shelved processing methods.

Cerebellar metastasis from papillary serous adenocarcinoma of the ovary mimicking Ménière's disease. A case report

BACKGROUND

In rare cases, cerebellar metastasis originating in serous papillary adenocarcinoma of the ovary can mimick Ménière's disease.

CASE

A 51-year-old woman, with complete remission after optimal maximal debulking and chemotherapy for an International Federation of Gynecology and Obstetrics IIIc primary ovarian carcinoma, presented with nausea, vomiting, vertigo and headache 18 months after surgery. Investigations revealed a solitary cerebellar cystic mass, 4.6 x 4.0 x 3.2 cm. Gross total excision of the cerebellar lesion followed by brain irradiation resulted in complete resolution of her symptoms. Histology showed a metastatic tumor consistent with the primary ovarian carcinoma.

CONCLUSION

In an atypical presentation in patients with metastatic ovarian carcinoma, thorough investigations should be done to rule out or confirm brain metastasis, which can be aggressively managed to prevent serious consequences and improve outcome.

Effects of isomalto-oligosaccharides on bowel functions and indicators of nutritional status in constipated elderly men

OBJECTIVES

To evaluate effects of isomalto-oligosaccharides (IO) on the bowel function and nutritional status of elderly men.

METHODS

Seven older male subjects participated in this study that consisted of a 30-day control low fiber period followed by a 30-day IO-supplemented (10 g active components) experimental period. Bowel functions such as defecation, enema use and bloating were monitored daily. Fecal characteristics such as wet and dry stool weights, stool moisture, pH and short-chain fatty acid contents were determined on five-day fecal composites collected in each period. Feces were further fractionated into plant, bacterial and soluble fractions to determine the bases for the increase in stool weight. Nutritional status of subjects was assessed with anthropometric parameters, nutrient intake and biochemical measurements.

RESULTS

Incorporation of IO significantly increased the defecation frequency, wet stool output and dry stool weight by twofold, 70% and 55%, respectively. Fecal acetate and propionate concentrations significantly increased by nearly two and a half fold with IO supplement. The increase in stool bulk was mainly attributed by increased bacterial mass. Mean serum sodium concentration decreased in the experimental period while other blood characteristics did not change significantly. Anthropometric parameters and nutrient intake remained constant throughout the study.

CONCLUSIONS

Consumption of IO effectively improved bowel movement, stool output and microbial fermentation in the colon without any adverse effect observed in this study. Therefore, supplementation of IO into ordinary low fiber diets may be practical in relieving constipation in the elderly population.

Exposure assessment of indoor allergens, endotoxin, and airborne fungi for homes in southern Taiwan

This study was undertaken to examine the seasonal variations of domestic Der p 1, Der p 2, and endotoxin on mattress and airborne fungal concentrations in homes of asthmatic and nonasthmatic children in southern Taiwan, where temperature and relative humidity are usually high throughout the year. A group of asthmatic children (10-12 years old) were selected randomly based on a citywide questionnaire survey. The nonasthmatic children were chosen to be in the comparison group by matching in age, gender, and proximity of residence. Environmental sampling of domestic microbes was conducted once a month for a year. Twelve calendar months were grouped into spring, summer, fall, and winter according to weather data (mainly average temperature and humidity) from the Central Weather Bureau. Dust samples from a child's mattress and airborne samples from a child's bedroom were collected and analyzed for allergens of Der p 1 and Der p 2, endotoxin, and fungi respectively. Results show that about 65% of children's mattresses in our region have Der p 1 levels greater than 2 microg/g. It is also apparent that most airborne fungal concentrations found in homes of either asthmatic or nonasthmatic children are higher than the recommended levels of concern. The predominant genera are Cladosporium, Aspergillus, Penicillium, Alternaria, and yeast. In addition, seasonal effects seem to be a critical factor for the concentrations and distributions of domestic endotoxin in these study homes. The implication of long-term exposure to these high levels of environmental microbes and how their effects vary with seasons remain to be further characterized.

Inhibition of inducible nitric oxide synthase (iNOS) prevents lung neutrophil deposition and damage in burned rats

This study was designed to investigate the role of NO and effect of iNOS inhibitor on the lung neutrophil deposition and damage after burn. In Experiment 1, specific pathogen-free (SPF) Sprague-Dawley rats underwent 35% total body surface area (TBSA) burn. On the 4th, 8th, 16th, and 24th h after burn, blood was collected for peroxynitrite-mediated dihydrorhodamine 123 (DHR 123) oxidation assay, and lung tissues were harvested for myeloperoxidase (MPO) test and histologic study. Pulmonary microvascular dysfunction was quantitated by measuring the extravasation of Evans blue dye (EBD). In Experiment 2, S-methylisothiourea (SMT) was given (7.5 mg/kg, intraperitoneal immediately post-burn) to suppress iNOS activity. On the 8th h after burn, the effect of SMT on blood DHR 123 oxidation, lung MPO, lung damage, and lung iNOS expression were evaluated. Lung MPO activity increased up to a maximum of 2-fold 8 h after burn. Blood DHR 123 oxidation increased up to a maximum of 2-fold 8 h after burn. Lung permeability increased up to a maximum of 2.5-fold 4 h after burn. SMT significantly decreased lung MPO activity, blood DHR 123 oxidation, and lung permeability by 31%, 41%, and 54%, respectively. SMT markedly decreased the thermal injury-induced perivascular and interstitial inflammatory cell infiltration and iNOS staining in bronchiolar epithelium, endothelial cells, and perivascular and interstitial inflammatory cells. In conclusion, thermal injury induces blood DHR 123 oxidation, lung neutrophil deposition, lung iNOS expression, and lung damage. Peroxynitrite might play an important role in thermal injury-induced lung neutrophil deposition and damage. Specific inhibition of lung iNOS expression and blood DHR 123 oxidation with SMT on thermal injury not only attenuated the lung neutrophil deposition, but also reduced lung damage.

Association between obesity and hyperlipidemia among children

BACKGROUND

This study was undertaken to show the association between obesity and hyperlipidemia among the children.

METHODS

In March 2000, while conducting a comprehensive health examination, we analyzed 2011 children from the first grade of primary schools in Taichung City in Taiwan. To study the association between obesity and hyperlipidemia, the t test, chi-square analysis, and multivariate logistic regression were used.

RESULTS

There were 1057 boys (52.56 percent) and 954 girls (47.44 percent). The mean age was 7.27 +/- 0.46 years. The proportion of overweight was 11.07 percent in boys and 11.64 percent in girls. The proportion of obesity was 14.19 percent in boys and 12.89 percent in girls. After controlling the other covariates, the multivariate logistic regression analysis showed that overweight was associated with a low level of high density lipoprotein cholesterol. Obesity was associated with hypertriglyceridemia, a high level of low density lipoprotein cholesterol, and a low level of high density lipoprotein cholesterol.

CONCLUSIONS

Our findings disclosed that the prevalence of overweight and obesity was high in childhood. Early intervention to control and prevent childhood obesity might be warranted. Obesity was associated with hyperlipidemia in children. A wide-scale survey will be suggested in the future to establish causal-effect issues between obesiyy and hyperlipidemia.

Frequency doubling technology perimetry in retinal diseases--preliminary report

The role of frequency doubling technology perimetry (FDT) in glaucoma has been promising in speed and simplicity as well as in its high sensitivity and specificity compared to conventional automatic perimetry. In this study, we evaluate the role of frequency doubling technology perimetry (FDT) in a variety of retinal diseases. FDT using full-threshold C-20 mode was performed in thirty-three patients with a variety of retinal diseases [16 cases of rhegmatogenous retinal detachment (RRD), nine cases of age-related maculopathy (AMD) and eight cases of central serous chorioretinopathy (CSCR)]. The fundus was scored by the extent of disease on each quadrant and macular area (central five degree visual angle). Then the retinal scores were compared with the points depressed to 2% on total deviation plots in FDT C-20 full-threshold mode using Spearman's rank correlation method. The correlation was statistically significant in the group of RRD (R = 0.57, P = 0.01), whereas the correlation was not significant in the group of macular diseases (AMD & CSCR, R = 0.47 & 0.32, P = 0.12 & 0.20). In conclusion, our results suggest that FDT might be a useful and simple technique for functional evaluation in RRD, but not in the macular disease group under this scoring system.

[Expression of autoantibodies to ICA512 and GAD in the sera of patients with diabetic ketoacidosis or ketonemia]

To explore the expression of the autoantibodies to ICA512 and GAD65 in the sera of diabetic patients who will be diagnosed as Type 1 diabetes, autoantibody assays were carried out in 15 diabetic patients complicated with ketonemia or ketoacidosis and in 19 healthy controls. The results were that the positive ratios of these autoantibodies were higher in the patient's sera than in the control's, and were higher in patients with shorter disease duration than those with longer disease duration. It is suggested that detecting these autoantibodies is helpful to the classification of diabetes and the disease duration affects the antibody's positive ratio.

Hepatitis B vaccination and hepatocellular carcinoma rates in boys and girls

CONTEXT

Hepatocellular carcinoma (HCC) has a male predominance and is closely related to hepatitis B virus (HBV) infection. Hepatitis B virus vaccination was launched in 1984 in Taiwan for neonates of mothers carrying hepatitis B e antigen, resulting in a decreased incidence of HCC in children. The effect on boys vs girls is not known.

OBJECTIVE

To evaluate the association between a HBV vaccination program with incidence of childhood HCC by sex.

DESIGN AND SETTING

Analysis of data collected from Taiwan's National Cancer Registry System and the Taiwan Childhood Hepatoma Study Group between 1981 and 1996.

PARTICIPANTS

Children aged 6 to 14 years who were diagnosed as having HCC (201 boys and 70 girls).

MAIN OUTCOME MEASURE

Incidence of HCC in boys and girls before and after implementation of the vaccination program.

RESULTS

The boy-girl incidence ratio decreased steadily from 4.5 in 1981-1984 (before the program's introduction) to 1.9 in 1990-1996 (6-12 years after the vaccination program was launched). The incidence of HCC in boys born after 1984 was significantly reduced in comparison with those born before 1978 (relative risk [RR], 0.72; P =.002). No significant decrease in HCC incidence was observed in girls born in the same periods (RR, 0.77; P =.20). The incidence of HCC in boys remained stable with increasing age, while an increase of HCC incidence with age in girls was observed. These age and sex effects remained the same regardless of birth before or after the vaccination program.

CONCLUSION

Our results suggest that boys may benefit more from HBV vaccination than girls in the prevention of HCC.

Human peritoneal mesothelial cells produce nitric oxide: induction by cytokines

OBJECTIVE

To investigate the induction of nitric oxide synthase type II (iNOS) in human peritoneal mesothelial cells (HPMC) using cytokines and bacterial lipopolysaccharide (LPS).

DESIGN

Confluent monolayers of HPMC were exposed to cytokines [tumor necrosis factor alpha (TNFalpha), interleukin-1 beta (IL-1beta), interferon gamma (IFNgamma)] or LPS, individually or in various double and triple combinations, for 24-72 hours. Concentrations of nitrate and nitrite in the media were quantified using the Griess reaction and used as indirect indices of nitric oxide (NO) production. The expression of iNOS was assessed using reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot.

RESULTS

Neither single cytokines nor LPS was able to induce iNOS mRNA or NO production. Both double combinations of TNFalpha + IFNgamma and IL-1beta + IFNgamma were able to induce iNOS mRNA expression, but only TNFalpha + IFNgamma induced significant NO production. The triple combination of TNFalpha + IFNgamma + IL-1beta induced even more NO production than TNFalpha + IFNgamma. There was no constitutive NO synthase type III (eNOS) expression in HPMC.

CONCLUSIONS

Certain combinations of cytokines could stimulate cultured HPMC to produce NO, and HPMC might be a source of intraperitoneal NO production during peritonitis.

Right middle lobe atelectasis associated with endobronchial silicotic lesions

BACKGROUND

In a period of 18 months, we have encountered 4 cases of right middle lobe atelectasis associated with endobronchial silicotic lesions of right middle lobe bronchi. All patients had occupational exposure to mineral dusts (3 coal miners and 1 sand blaster) for months to decades.

METHODS

The nature of the endobronchial silicotic lesions that caused the bronchial obstruction has been confirmed by endobronchial biopsies and energy-dispersive spectrometry of the lesions. Extrinsic compression has been excluded by careful radiographic and computed tomographic image analysis.

RESULTS

The endobronchial silicosis does not appear to correlate with the degree of pneumoconiosis of the lung parenchyma. The endobronchial silicosis may cause bronchial obstruction in the absence of radiographic evidence of pulmonary silicosis.

CONCLUSION

The endobronchial silicosis and consequent lung atelectasis may be associated with silica exposure.

[Change of bone mineral density in type 2 diabetes mellitus with nephropathy]

OBJECTIVE

To investigate into the changes of bone mineral density(BMD) in Type 2 diabetes mellitus with nephropathy(DN) and without nephropathy(DM).

METHODS

BMD of lumbar vertebrae 1-4 and femur in 93 cases of Type 2 diabetes mellitus(41 cases of DN and 52 cases of DM) were measured with dual energy x-ray absorptiometry(DEXA) and were compared with age, sex, and BMI-matched normal control group.

RESULTS

No significant differences were found in BMD of femoral total, neck, L1-L4 between DM and normal controls in females(P > 0.05). DM in men had higher BDM at L2, femoral total neck than normal controls(P < 0.05). BMD at femoral total, neck, in females and L1-L4 femoral total neck in men in DN group were lower than DM group, but had no statistical differences.

CONCLUSION

The changes in BMD of above areas in DM were normal and higher because of different areas. BMD in DN had lower predisposition.

Immunogenicity and reactogenicity of the combined hepatitis A and B vaccine in young adults

The combination of hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccinations can offer convenience, increased compliance and cost saving. We have studied the immunogenicity, reactogenicity and safety of combined hepatitis A and B vaccination in young adults (16-35 years old). Eighty healthy young adults were divided into two random groups. One group received the combined hepatitis A and B vaccine (HAB) in one arm while the other group was administered concomitant hepatitis A and B vaccines (HAV + HBV) in the right and left arms, respectively. The immunogenicity, reactogenicity and safety were assessed after each dose in both the groups. In local symptoms, the percentage of the combined HAB group was lower than the HAV + HBV group, and the general symptoms were noted in approximately 30% of each group without any significant difference. No serious adverse effects were noted. All the subjects were seropositive for antibody to hepatitis A virus (anti-HAV) after one dose of vaccine, and remained seropositive after three doses in both groups. The seropositive rate for antibody to hepatitis B surface antigen (anti-HBs) was significantly higher (84%) in the combined HAB group than the concomitant HAV + HBV group (62%), (p<0.05) after dose two, and all the subjects were seropositive (100%) after the third dose. The GMTs of anti-HAV and anti-HBs were not significantly different between groups 1 and 2 (p>0.1) except in month 6 when the GMT of anti-HBs was higher in HAB group (p=0.0039). The combined HAB vaccine was found to be safe, well tolerated and had less local symptoms in young adults. The immunogenicity and reactogenicity were similar to the concomitant HAV + HBV vaccines.

Growth enhancement of fowls by dietary administration of recombinant yeast cultures containing enriched growth hormone

In present study the methylotrophic yeast, Pichia pastoris, was used to express a recombinant growth hormone (rGH) gene of swine. A synthetic secretion cassette was constructed using the promoter of the alcohol oxidase1 gene (AOX1), and a alpha-factor signal peptide. After electroporatic transformation and zeocin selection, several clones exhibited high levels of rGH protein expression constituting more than 20% of total yeast protein. Over 95% of rGH was shown to be export into the culture supernatant. Yeast transformant containing the highest recombinant growth hormone level (rGH yeast) and native GS115 Pichia pastoris (non-rGH yeast, as a control) were separately cultured, harvested and adsorbed by wheat bran. Yeast cultures of four dosages (0.05, 0.1, 0.2, and 0.4%) were mixed respectively with chick basal diet and fed to simulated country chickens for 9 weeks. The results showed that, when compared to control chicks, the percentage of body weight gain was improved significantly (P<0.05) in chicks fed with diets containing 0.1 or 0.2% rGH-rich yeast culture at brooding stage, and in chicks fed with 0.4% rGH-rich yeast culture at growing stage. The average weight gain in rGH yeast treated groups for the full-term (0 to 63d) and short term (43 to 63d) of growth were 10.6 and 9.4%, respectively, better than the non-rGH yeast control group. These experimental data suggest that the use of rGH-containing yeast as a supplement in fed provided an alternative approach for growth improvement in simulated country chickens.

Down-regulation of N-acetylglucosaminyltransferase V by tumorigenesis- or metastasis-suppressor gene and its relation to metastatic potential of human hepatocarcinoma cells

The effects of transfection of the metastasis suppressor gene nm23-H1 and cell-cycle related tumor-suppressor gene p16 on the activity of N-acetylglucosaminyltransferase V (GnT-V) and their relations to cancer metastatic potential were investigated. After transfection of nm23-H1 into 7721 human hepatocarcinoma cells and A549 human lung cancer cells, the activities of GnT-V were decreased by 28%-42% in the cells. In contrast, when p16 was transfected into these two cell lines, the decrease of GnT-V activity was only observed in A549 cells. This was probably to be due to the obvious expression of p16 gene in parental 7721 cells and the deletion of p16 in A549 cells. The decrease of GnT-V mRNA was only observed in nm23-H1-transfected cells, but not in p16-transfected A549 cells, suggesting that these two genes regulated GnT-V via different mechanisms. Horseradish peroxidase (HRP)-lectin staining showed that the 7721 cells transfected with nm23-H1 or the A549 cells transfected with p16 displayed a decreased intensity with HRP-leucoagglutinating phytohemagglutinin and increased intensity with HRP-concanavalin A, indicating the decline of beta1,6 N-acetylglucosamine branching structure on the asparagine-linked glycans of cell-surface and intracellular glycoproteins. The nm23-H1 transfected 7721 cells also displayed some changes in metastasis-related phenotypes, including the increase in cell adhesion to fibronectin (Fn), the decline in cell adhesion to laminin (Ln), and the decreased cell migration and invasion through matrigel. Transfection of antisense GnT-V cDNA into 7721 cells resulted in a decrease of GnT-V activity, an increase of cell adhesion to Fn or Ln, and a decrease in cell migration and invasion through matrigel. These phenotypes bore similarity to those of the 7721 cells transfected with nm23-H1. Our findings indicate that the down-regulation of GnT-V by nm23-H1 contributes to the alterations in metastasis-related phenotypes, and is an important molecular mechanism of metastasis suppression mediated by nm23-H1.

Hereditary fructose intolerance presenting as Reye's-like syndrome: report of one case

Hereditary fructose intolerance (HFI) is an autosomal recessive disease caused by catalytic deficiency of aldolase B (fructose-1, 6-bisphosphate aldolase). Herein we report on a case of hereditary fructose intolerance with initial presentation of episodic unconsciousness, seizure, hypoglycemia, hepatomegaly, and abnormal liver function since the patient was 11 months old. She was diagnosed as Reye's-like syndrome according to a liver biopsy done at 20 months of age. As she grew up, cold sweating, abdominal pain or gastrointestinal discomfort shortly after the intake of fruits was noted and she developed an aversion to fruits, vegetables and sweet-tasting foods. At 9 years of age, a fructose tolerance test signified a positive result that induced hypoglycemia, transient hypophosphatemia, hyperuricaemia, elevation of serum magnesium, and accumulation of lactic acid. Appropriate dietary management and precautions were recommended. The patient has been symptom-free and exhibited normal growth and development when followed up to 12 years of age.

Long-term follow-up study of core gene deletion mutants in children with chronic hepatitis B virus infection

Core gene deletion mutants of hepatitis B virus (HBV) have been identified in adults. Because the acquisition of HBV occurs mainly in infancy and childhood in hyperendemic areas, this study aimed to learn the temporal profile of such mutants in children with chronic HBV infection. We have followed up 365 HBV-infected children for more than 10 years and screened out HBV core gene deletion from their sera. Serial serum samples of positive cases were subjected to HBV-DNA nucleotide sequence analyses and quantification. Deletion mutants were found in 18 of the 365 patients (4.9%). Most cases (15 of 18) with deletion mutants heralded hepatitis B e antigen (HBeAg) seroconversion phase, while the other cases (3 of 18) remained in HBeAg-seropositive phase. Deletion mutants disappeared after HBeAg seroconversion except in 1 child. Decreased HBV-DNA levels accompanied deletion mutants for those who finally underwent HBeAg seroconversion, but the HBV-DNA level did not decline if there was no seroconversion. Deletion mutants were not associated with a particularly high peak liver enzyme. Core gene deletion mutants could appear as early as the age of 5. The duration of their appearance was 0.5 to 5 years. Horizontal rather than perinatal transmission of HBV was a favorable factor for these mutants to develop. Deletion fragments were located in the middle part of core gene. The emergence of the mutants was likely the result of host-viral interaction and mostly signified HBeAg seroconversion within 1 year. Core gene deletion mutants appeared preferably in children acquiring HBV by horizontal transmission.

Modulation of the basal activity of phosphatidylinositol-3-kinase/protein kinase B signaling pathway in human hepatocarcinoma cells

The modulation of GnT-V activity by signaling molecules in PI-3-K/PKB pathway in human hepatocarcinoma cell line 7721 was studied. GnT-V activity was determined after the transfection of sense or antisense cDNA of PKB into the cells, as well as the addition of activators, specific inhibitors, and the antibodies to the enzyme assay system or culture medium. It was found that the basal activity of GnT-V was up regulated by the sense and down regulated by the antisense cDNA of PKB transfected into 7721 cells. GnT-V was activated by PIP2, PIP3 or GTPgamma[S] added to the assay system, and the activation of PIP2 or GTPgamma[S] was abolished by LY2940002, a specific inhibitor of PI-3-K, but the activation of PIP3 was not attenuated by LY2940002. In addition, GnT-V activity in cultured parental or H-ras transfected cells was inhibited by the antibody against PKB or PI-3-K. These findings demonstrated the involvement of PI-3-K/PKB signaling pathway in the regulation of GnT-V. Moreover, ET18-OCH3, an inhibitor of Raf translocation and PI-PLC enzyme, which produces the activator of PKC, as well as the antibodies against Raf-1 or MEK also inhibited GnT-V activity in the parental and H-ras transfected cells. The inhibitory rates, however, were less in the transfected cells than those in the parental cells. These results reveal that in parental and H-ras transfected 7721 cells, the basal activity of GnT-V is also regulated by the Ras/Raf-1/MEK/MAPK cascade in addition to PI-3-K/PKB signaling pathway. The significance of these two pathways in the regulation of GnT-V and their relations to the activation of PKC previously reported by our laboratory (Ju TZ et al., 1995 Glyconjugate J 12, 767-772) was discussed.

Effects of H-ras and v-sis overexpression on N-acetylglucosaminyltransferase V and metastasis-related phenotypes in human hepatocarcinoma cells

Oncogenes and N-acetylglucosaminyltransferase (GnT-V) are both commonly associated with carcinogenesis and metastasis. In order to elucidate the relationship between oncogenes and GnT-V, two oncogenes, H-ras and v-sis/PDGF (platelet-derived growth factor), were selected, and the effects of their overexpression on GnT-V in 7721 human hepatocarcinoma cells were investigated. The results showed that the over expression of H-ras or v-sis/PDGF-B up-regulated the activities of GnT-V to various degrees in the transfected cells. In H-ras- and PDGF-B-overexpressing cells, the activity of GnT-V was up-regulated to double the normal value. The transient expression of v-sis, which produces a protein almost identical to PDGF-B, stimulated the GnT-V activity by 80.3%, and the effect was more pronounced (increased by 182.5%) in 7721 cells with stable expression of v-sis. The stimulating effect was entirely abolished by treatment with PDGF-B antibody. The staining of asparagine-linked glycans (N-glycans) in the H-ras- and v-sis-overexpressing 7721 cells was intensified when horseradish peroxidase-labeled leucoagglutinating phytohemogglutinin was used as a probe, indicating the increased content of beta1,6GlcNAc branching on the N-glycans. The enhancement of GnT-V mRNA expression was also observed in H-ras- and v-sis- overexpressing cells, indicating that H-ras and v-sis regulated GnT-V via the transcription of GnT-V mRNA and the synthesis of GnT-V protein. The cells overexpressing H-ras and v-sis displayed some changes in metastasis-related phenotypes, including acceleration of cell growth, decline of cell adhesion to fibronectin, and an increase of cell adhesion to laminin, as well as increased invasiveness through Matrigel. These results indicated that the alteration of cell adhesion and invasion induced by oncogenes is closely related to the up-regulation of GnT-V activity and its product, beta1,6GlcNAc branching in N-glycans on the cell surface.

Transcriptional repression of p21((Waf1/Cip1/Sdi1)) gene by c-jun through Sp1 site

Previously, we found that c-jun represses the tumor suppressor p21((Waf1/Cip1/Sdi1)) (p21) gene expression. In this study, we further investigated the mechanism of the inhibitory effect of c-jun on p21. After analysis of a series of deletion and point mutants of p21 promoter, we found that Sp1-3 site (-77 and -83) relative to the transcription start site played an important role for c-jun-repressing-responsive element in the p21 promoter. Both Sp1 and Sp3 transcription factors were the key factors for this event. However, the data from electrophoretic mobility shift assay indicated that c-jun did not change the Sp1 DNA-binding affinity, suggesting that additional factors may be involved in the repression of p21 by c-jun. Furthermore, c-jun could inhibit butyrate-inducing p21 gene expression through Sp1, indicating at least one common pathway whereby p21 expression is affected by c-jun and butyrate in opposing actions. Moreover, the hyperphosphorylated retinoblastoma protein (Rb) increased in c-jun expressing cells, indicating that phosphorylated Rb may play a role in regulating Sp1 to repress p21 expression. This is the first demonstration of how housekeeping factors and oncogene product counteract the function of tumor suppressor genes to control cell cycle progression.

[Contents of general flavonoides in Epimedium acuminatum Franch. and its differently-processed products]

OBJECTIVE

Determining and comparing the contents of general flavonoides in four kinds of differently-processed products of Epimedium acuminatum.

METHOD

Determining the contents by ultraviolet spectrophotometry.

RESULT

The contents were found in the following seguence: unprocessed product, clearly-fried product, alcohol-broiled product, salt-broiled product, sheep-fat-broiled product. The average recovery rate was 96.01%, with a 0.74% RSD(n = 5).

CONCLUSION

Heating causes the contents of general flavonoides in the processed products to decrease. These processed products are still often used in clinical treatment, for the reason that the adjuvant features certain coordinating and promoting functions. The study is to be pursued further.

Regulation of phospholipase D from human hepatocarcinoma cell line by purine nucleotides and protein kinase A

The regulation of phosphatidylcholine-specific phospholipase D by purine nucleotides and protein kinase A were studied in vitro using an enzyme preparation partially purified from the membranous fraction of 7721 hepatocarcinoma cells. It was found that the enzyme activity was elevated by low concentrations of some purine nucleotides, but the activating effects were decreased when the concentrations of the nucleotides were higher. The optimal concentrations of GTP, GTPgamma[S], GDP and ATP for maximal activation were 0.1 mM, 5 microM, 1 mM and 1 mM respectively. The activation caused by 1 mM ADP was lower. The enzyme was not activated by 1 mM AMP, but significant activation was observed by the addition of 1 mM cAMP. The latter was mediated by protein kinase A, as a specific inhibitor of protein kinase A abolished the activation. There were synergic effects between ATP and GTP, ATP and PIP2, but not between ATP and GTPgamma[S], or PIP2 and GTPgamma[S]. The activating effects of GTP and ATP were abolished by neomycin, a PIP2 scavenger. These results suggest that phospholipase D is regulated by GTP-binding protein and the presence of PIP2 is required for the activation induced by GTP. Protein kinase A may be another protein kinase in addition to protein kinase C and protein tyrosine kinase which regulate the activity of phospholipase D, when the intracellular concentration of cAMP is increased.

Opposing changes in N-acetylglucosaminyltransferase-V and -III during the cell cycle and all-trans retinoic acid treatment of hepatocarcinoma cell line

The changes in N-acetylglucosaminyltransferase-V and -III (GnT-V, GnT-III) during the cell-cycle of synchronized 7721 human hepatocarcinoma cell line were investigated. Using an HPLC method to assay GnT and flow cytometry (FCM) for cell cycle analysis, it was found that GnT-V showed the highest activity, but GnT-III reached the lowest activity when G(2)/M cells were most abundant. In contrast, GnT-V declined to the minimum while GnT-III elevated to maximum when G(0)/G(1) cells were most predominant. The opposing changes were more obvious when the activities of GnT-V and GnT-III were expressed as relative activities (activity of GnT-V or GnT-III/the sum of activities of GnT-V plus GnT-IV plus GnT-III). These opposing changes of GnT-V and GnT-III during the cell cycle might result from the different regulatory mechanisms of GnT-V and GnT-III expression in the cell cycle. The alterations in the structures of cell surface N-glycans were compatible with the changes of the activities of GnTs. The results from immunocytochemistry and Northern blot showed that the protein and mRNA contents of GnT-V were not significantly changed during the cell cycle. The activity of a cell cycle regulating protein kinase, p34(cdc2) kinase, correlated to the activity of GnT-V. These findings suggested that the change of GnT-V activity in cell cycle was not the consequence of the alteration of gene transcription or enzyme protein synthesis, but might be caused by the post-translational regulation. The decrease in GnT-V and the corresponding increase in GnT-III activities were also found after the cells were treated with all-trans retinoic acid (ATRA), and the mechanism of this might be different from that in the cell cycle.

Effects of all-trans retinoic acid and epidermal growth factor on the expression of nm23-H1 in human hepatocarcinoma cells

The effects of all-trans retinoic acid (ATRA) and epidermal growth factor (EGF) on the expression of nm23-H1, a metastasis suppressor gene, were studied in a human 7721 hepatocarcinoma cell line. It was discovered that the expression of nm23-H1 mRNA was up-regulated by ATRA. This was compatible with the observation that the metastasis-associated phenotypes, such as chemotaxic cell migration and invasion, were both reduced in the ATRA-treated and nm23-H1-cDNA-transferred 7721 cells. However, ability of cells to adhere to fibronectin and laminin was not altered identically in the ATRA-treated and nm23-H1-cDNA-transfected 7721 cells. In contrast, the expression of nm23-H1 mRNA in 7721 cells was down-regulated both by the treatment with EGF and by the transfection of c-erbB-2/neu cDNA, which codes a protein homologous to the EGF receptor. EGF is a compound with biological effects opposite to those of ATRA, and c-erbB-2/neu is known to be a metastasis-promoting gene. These results reveal that the metastasis-preventing effect of ATRA may partly result from the up-regulation of nm23-H1, and the metastasis-promoting effects of EGF and c-erbB-2/neu were probably mediated in part by the down-regulation of nm23-H1.