Digital filter design for peak detection of surface EMG

A simple Low-Pass Differential (LPD) filter is often used for the Motor Unit Action Potential (MUAP) peak detection in needle EMG decomposition. Decomposition of surface EMG is much more difficult since surface EMG is more mixed than needle EMG. A successful peak detection of MUAPs is a first important step for EMG decomposition. We found that a simple LPD filter is not suitable for surface MUAP detection; instead the Weighted Low-Pass Differential (WLPD) filters are proposed. The filter performance is analyzed based on different window selection and varying MUAPs from simulated and recorded surface EMG. The sinusoidal WLPD filter is found to have better SNR improving factors, and to be more robust under the varying conditions.

[Study on green upconversion luminescence of fluoride glasses doped with Nd3+]

In this paper, we report the upconversion luminescence of Nd: fluoride glasses pumped with 858 nm diode laser. Among the observed upconversion spectra, the green emission concerning with three photon process has overwhelming superiority in intensity, when the doping concentration of Nd3+ is enhanced, the green upconversion emission increases more drastically than that of other upconverted emissions. The experiment results indicate that fluoride glasses doped with Nd3+ posssess possibility of being green emitting upconversion materials. When the upconversion mechanism is discussed, the green luminescence concerning with three-photon is ascribed to three-ion cooperative upconversion.

Effect of artemether against Schistosoma haematobium in experimentally infected hamsters

The drug, artemether, has been shown to be active against the juvenile stages of Schistosoma japonicum and Schistosoma mansoni in experimentally infected animals, while it is less effective on adult worms. These findings have been confirmed in randomised controlled trials in humans. Consequently, it could be expected that artemether is also active against Schistosoma haematobium. We present here the first results from experiments assessing the effect of artemether on S. haematobium. Hamsters with a single infection received intra-gastrically an initial dose of 300 mg/kg artemether on day 14, 21 or 28, followed by further doses at varying treatment regimens. In all the treatment groups, the total and female worm reduction rates were highly significant, and ranged from 78 to 100% in hamsters harbouring juvenile schistosomes. Hamsters infected three times with S. haematobium, on days 0, 4 and 9, and repeatedly treated with artemether at the same dose as above, showed highly significant total and female worm reduction rates of between 94 and 99%. Artemether was also active against 77-day-old adult S. haematobium, since its administration on two consecutive days resulted in highly significant total and female worm reduction rates of 76-89%. Our findings confirm that artemether is also active against S. haematobium, especially the schistosomules. These results provide a basis for clinical trials in humans, for further assessment of the potential of artemether for schistosomiasis control.

ZNF198-FGFR1 transforming activity depends on a novel proline-rich ZNF198 oligomerization domain

An acquired chromosomal translocation, t(8;13)(p11;q11-12), observed in a distinctive type of stem cell leukemia/lymphoma syndrome, leads to the fusion of the 5' portion of ZNF198 and the 3' portion of FGFR1. ZNF198-FGFR1 fusion transcripts encode 4 to 10 zinc fingers, a proline-rich region, and the intracellular portion of the FGFR1 (fibroblast growth factor receptor 1) receptor tyrosine kinase. We demonstrate that the ZNF198 proline-rich region constitutes a novel self-association domain. When fused to the intracellular domain of FGFR1, the ZNF198 proline-rich region is sufficient to cause oligomerization, FGFR1 tyrosine kinase activation, and transformation of Ba/F3 cells to IL-3 independent growth. (Blood. 2000;96:699-704)

Transfection and expression of HCV-NS5B gene in Huh-7 cells

OBJECTIVE

To study the mechanism of hepatitis C virus (HCV) replication and to test gene therapy for hepatitis C, a human liver cell line expressed HCV RNA polymerase has been established.

METHODS

NS5B gene has been transfected into Huh-7 cells by lipofectamine. The results of transfection were confirmed by PCR and Southern blot analysis, and the level of the non-structural protein 5B (NS5B) in Huh-7 cells was detected by Western blot analysis.

RESULTS

There were NS5B gene fragments and the expression of NS5B protein in Huh-7c cells transfected with pTeT-NS5B or pcDNA-NS5B plasmid.

CONCLUSIONS

We have established a HCV RNA polymerase expression system in Huh-7 cells which can be further used to analyze the mechanism of HCV replication and provide a cell model for gene therapy in vitro.

Tegumental changes in 21-day-old Schistosoma mansoni harboured in mice treated with artemether

Alterations in the tegument of 21-day-old Schistosoma mansoni, caused by artemether administered to the infected mice, were studied using scanning electron microscopy (SEM). Mice were infected with S. mansoni cercariae, and after 21 days a single dose of artemether (400 mg/kg) was administered intragastrically. After 24, 72 h and 7 days groups of three mice were killed and the schistosomules collected by perfusion, fixed and processed routinely, and examined by SEM. After 24 h, all male and female worms examined showed alterations in the tegument, characterised by swelling, vesiculation and fusion of tegumental ridges; peeling, erosion and collapse of damaged tegumental surface, and also destruction of the oral sucker and acetabulum. After 72 h, severe damage to the tegument was seen, usually including extensive peeling, swelling and vesiculation, and host leukocytes were adhered to the damaged surface. Some worms were surrounded by clusters of host leukocytes or had even disintegrated. Seven days after treatment, some schistosomules still showed severe tegumental damage, but in some cases the damage was less than at earlier times, which suggested that those schistosomules that had survived were beginning to recover. The ability of artemether to cause severe damage to the tegument correlates with its high efficacy in killing 21-day-old schistosomules.

Oral artemether for prevention of Schistosoma mansoni infection: randomised controlled trial

BACKGROUND

Chemotherapy with praziquantel is the current strategy of choice to control schistosomiasis. However, in view of concern about praziquantel tolerance or resistance, new drugs are needed. Artemether, a derivative of the antimalarial drug artemisinin, kills immature schistosomes of Schistosoma japonicum, and reduces the incidence of infection in field trials. Laboratory studies have also showed activity by this drug against S. mansoni. We report a randomised double-blind placebo-controlled clinical trial of artemether to prevent S. mansoni infection.

METHODS

The trial was done in an area of western Côte d'Ivoire endemic for S. mansoni. 354 schoolchildren were enrolled. Stool specimens were screened over four consecutive days, followed by two mass treatments with praziquantel 4 weeks apart. All S. mansoni negative children were randomly assigned to placebo (n=151) or artemether 6 mg/kg (n=138) orally six times once every 3 weeks. Adverse events were assessed 24 h after treatment. Perceived illness episodes were recorded once a week by interviewing the children with a standardised questionnaire. 3 weeks after the final medication S. mansoni infections were assessed by screening stool samples. Blood samples were examined for Plasmodium falciparum before the first and after the last artemether treatment.

FINDINGS

Oral artemether showed no adverse reactions. The group that received artemether had a significantly lower incidence of S. mansoni infection (31/128 versus 68/140, relative risk: 0.50 [95% CI 0.35-0.71], p=0.00006). The geometric mean egg output among positive children in the artemether group was significantly lower than in placebo recipients (19 vs 32 eggs/g stool, p=0.017). There was also a significant reduction in the prevalence of P. falciparum.

INTERPRETATION

Oral artemether is safe and shows a prophylatic effect against S. mansoni. The use of artemether may be recommended in appropriated situations as an additional tool for more effective schistosomiasis control measures. However the application needs to be carefully assessed especially in view of the concern that it could select for resistant plasmodia.

Role of activator protein-1 in TCR-mediated regulation of the murine fasl promoter

The present study demonstrates that transcription factor interactions are important in regulating the murine fasl promoter following TCR-mediated activation. We used DNase I-footprinting, EMSAs, and transient transfection assays to identify the minimal TCR signal-responsive region within the fasl promoter. This region contains the previously identified binding sites for NF-kappaB and Egr and the AP-1 site identified in this study. We found that TCR signaling induces AP-1 binding to this site and regulates the fasl promoter function in a fashion dependent on NF-kappaB binding. However, mutation in the AP-1 site alone did not show a significant effect on the promoter function. The data suggest that the minimal promoter required at least two transcription factors to function.

KIT extracellular and kinase domain mutations in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms arising in the gastrointestinal tract. GISTs express the KIT receptor tyrosine kinase, and many cases have activating mutations in the KIT juxtamembrane region. We now report an analysis of KIT cDNA and genomic sequences in eight GISTs that lack juxtamembrane region mutations. Six cases contained heterozygous exon 9 mutations in which six nucleotides, encoding Ala-Tyr, were duplicated. The other two cases contained homozygous exon 13 missense mutations, resulting in substitution of Glu for Lys(642), that were associated with constitutive KIT tyrosine phosphorylation. Sequence analysis of DNAs from nonneoplastic companion tissues revealed that both the exon 9 and exon 13 mutations were somatic. These are the first descriptions, in any tumor, of mutations in KIT exons encoding the C-terminal end of the extracellular domain and the first part of the split kinase domain. These findings indicate that KIT may be activated by mutations in at least three domains-extracellular, juxtamembrane, and kinase-in GISTs.

[The influence of external stimulation on content and quality of volatile oil in Lignun Santali albi]

The authors analyzed the quality of Ligmum Santali Albi formed by the external stimulation of hormone and windburn by GC-MS-DS. The results showed that the content of volatile oil is 2.34% in the heart wood formed in 10 years tree age of Santalum album (SA) after 2 years stimulation continuously with a definite concentration of hormone, which is near to the 25 years tree age of SA in the same place. The GC-MS analysis showed that the content of santalol and other chemical components in volatile oil are similar to the 25 years tree age of SA. It is indicated that a definite concentration of hormone stimulated the SA may shorten the formation of the heart wood. The heart wood can be also formed by the broken branches after 2 years windburn, but its content of volatile oil is only 1/2 of the heart wood formed by hormone stimulation.

Plasma from ESRD patients inhibits nitric oxide synthase activity in cultured human and bovine endothelial cells

Our recent observations of reduced total nitric oxide synthesis in renal failure patients on peritoneal dialysis and haemodialysis suggest that hypertension in end-stage renal disease involves lack of vasodilatory endothelial NO. To directly test this, uraemic plasma was obtained from dialysis patients and incubated with cultured vascular endothelial cells, to determine the effect on nitric oxide synthase (NOS) activity in comparison with plasma from subjects with normal renal function. After incubation for 6 h with 20% uraemic plasma from peritoneal dialysis and immediately prehaemodialysis patients, NOS activity was reduced in human dermal microvascular endothelial cells. Haemodialysis did not remove the NOS-inhibitory activity of uraemic plasma nor did it activate inducible NOS, as NOS activity was always similar in control and dexamethasone pretreated cells. Nitric oxide production (accumulation of nitrite and nitrate) was lower in cells incubated with uraemic vs. normal plasma and excess arginine increased nitric oxide production by cells previously exposed to uraemic medium. This inhibitory effect was not associated with co-factor deficiency but did correlate with plasma concentrations of endogenous NOS inhibitors. These in vitro findings suggest that low endothelial NOS activity may contribute to hypertension in end stage renal disease patients.

Analysis of related factors in complications of stereotactic radiosurgery in intracranial tumors

OBJECT

To investigate the related factors in complications of stereotactic radiosurgery for intracranial tumors.

METHODS

A retrospective review of 146 patients with intracranial tumors treated with stereotactic radiosurgery was conducted. Sixty-five patients received single-dose treatment and the rest received fractionated stereotactic radiosurgery. Ninety-five patients received conventional radiotherapy in the meantime.

RESULTS

Follow-up period was 18-54 months. Follow-up rate was 92.5% and 39 patients (26.7%) had different complications. The Cox statistics showed that target volume, target peripheral dose, target maximal dose, and ratio of maximal dose to peripheral dose are related to the complications. Conversely, neither type of tumor disease, gender, radiation schedule with or without conventional radiotherapy, target minimal dose, nor ratio of target peripheral isodose volume to target volume were found to be related to complications.

CONCLUSION

Target volume and dose are the major factors causing complications, and the optimization of the therapeutic planning can play a significant role in reducing them.

Clinical and CT histological diagnosis of orbital tumors

The clinical manifestation and characteristics of CT image of 117 cases of orbital tumors in our hospital were investigated. The hemangioma had the highest incidence, and the less common tumors were, in sequence of incidence, pseudotumor, dermoid cysts, neurilemmoma, polymorphous adenoma and meningioma. The sensitivity in diagnosis of orbital tumor by CT was 93.3%. The coincidence of CT histological diagnosis with pathology were 83.3%, 82.6% and 71.4% for dermoid cysts, hemangioma, and pseudotumor respectively, but the general coincidence of CT histological diagnosis with pathology was only 67.8%. When CT was combined with ultrasound, cytological examination and clinical manifestations, the accuracy of histological diagnosis could be improved to 83.3%.

Length of protection by murine vaccination with living infective third-stage hookworm larvae

OBJECTIVE

To determine the length of protection by murine immunization with living third-stage hookworm larvae (L3) as measured by reduction in worm burden and host serologic antibody responses.

METHODS

Outbred male (Kunming strain) mice were immunized subcutaneously with 500 L3 once every 2 weeks for a total of immunization for 3 times, and then challenged orally with 1000 L3 for 1 to 8 weeks after the final immunization. Host protective immunity was determined both by the reduction in worm burden as measured by the number of L3 recovered from murine lungs 48-hour post-challenge, as well as by measurement of circulating antibodies. Histopathological responses were also examined. Non-immunized mice served as negative controls.

RESULTS

The protection by L3 immunization declined over time. One or 2 weeks after the final immunization, worm burdens were reduced 72% and 77.5% after challenge respectively. In contrast, only 37% reduction in worm burden was observed when the L3 challenge was delayed by 4 weeks and protection was almost entirely lost when there was an 8 week delay between the time of final immunization and challenge. The reduced level of protection over time partially correlated with diminishing L3-specific antibody responses. Host inflammation in the lungs of immunized mice also diminished.

CONCLUSION

The protection afforded by living L3 immunization is maximal for the first two weeks after immunization, but then declines significantly over the ensuing weeks.

Comparison of Erysiphe cichoracearum and E. cruciferarum and a survey of 360 Arabidopsis thaliana accessions for resistance to these two powdery mildew pathogens

In previous work, UEA1 and UCSC1, two geographically distinct, powdery mildew isolates, were recognized for their ability to infect Arabidopsis thaliana. We have clarified the identity of these isolates by determining their host ranges, reexamining their morphology, and comparing their DNA sequences for the 5.8S ribosomal RNA and two flanking internal transcribed spacer sequences. These experiments confirm that UEA1 is a member of Erysiphe cruciferarum and that UCSC1 belongs to E. cichoracearum. Interactions of the two Erysiphe isolates with 360 A. thaliana accessions were examined to provide a comprehensive profile of naturally occurring powdery mildew resistance in this weedy species. The majority of A. thaliana accessions (213) were susceptible to both isolates. Among the accessions exhibiting some degree of resistance, most (84) responded differentially to UEA1 and UCSC1 and the remainder were resistant to both isolates. Notably, resistance to UCSC1 cosegregated with RPW7, a locus previously demonstrated to confer resistance to UEA1 in Ms-0 x Landsberg (erecta) crosses. With this large collection of resistant accessions, questions about species specificity, genetic diversity and the evolution of resistance to powdery mildews can be addressed.

[DNase I sensitivity of nucleus and chromatin in six different tissues of old rates]

In order to investigate the mechanism of aging, we studied the DNase I sensitivity of nucleus and chromatin in six different tissue (heart, liver, spleen, lung, kidney and brain of old and weanling wistar rats. The results showed that the DNase I digestive sensitivity levels of nucleus and chromatin in the tissue of the old rats were lower than those of the weanling rats respectively that in the old rats, the DNase I digestive sensitively in the tissue varied, the lowest sensitivity was in brain (P < 0.01); and that in the weanling rats, lowest DNase I digestive sensitivity of nucleus and chromatin was also in the brain, but the difference was not significant.

FasL promoter activation by IL-2 through SP1 and NFAT but not Egr-2 and Egr-3

Recently activated peripheral T cells treated with IL-2 for 4 days expressed Fas ligand (FasL)-mediated cytotoxicity. These IL-2-treated T cells had high nuclear expression of SP1 and NFAT, but lacked the Egr-2 and Egr-3 that could be induced by anti-CD3 stimulation and had been implicated in FasL gene activation. A minimal promoter region that responded to IL-2 was identified by transient transfection assays using deletion mutants. The data suggests that the GGGCGGAAA site present in the 5' end of the minimal FasL promoter is critical to IL-2-induced FasL gene activation. The GGGCGGAAA sequence contains an overlapping site used by two transcription factor families, one (GGGCGG) for the SP1 family and the other (GGAAA) for the NFAT family. FasL promoter activity was partially but statistically significantly reduced with constructs mutated at either site. More activity was lost with a construct mutated at both sites. In contrast, mutation at the Egr site had no effect on IL-2-induced FasL promoter activity. Our study identified a new FasL promoter site responding to IL-2-induced SP1 and NFAT factors. Furthermore, the nuclei of IL-2-treated cells express SP1 and NFAT, but not Egr-2 and Egr-3, for FasL gene activation.

Cutaneous and subcutaneous mast cell and eosinophil responses after challenge in mice vaccinated with living infective third-stage hookworm larvae

OBJECTIVE

To examine the quantitative and qualitative alterations in mast cells and eosinophils distributed in the cutaneous and subcutaneous tissues of hookworm-infected, uninfected and vaccinated mice.

METHODS

Outbred male Kunming strain mice, weighing 18-22 g, were vaccinated thrice by subcutaneous inoculation with 500 living third-stage infective larvae (L3) of Ancylostoma caninum (A. caninum) every 2 weeks, and then challenged subcutaneously with 500 L3 one week after the final immunization. Uninfected mice and non-immunized mice but infected with L3 served as controls. The abdominal skin at the site of percutaneous entry was excised from challenged mice at intervals between 6 hours and 7 days after challenge, fixed, and then examined by light microscopy after staining with either toluidine blue or hematoxylin and eosin.

RESULTS

The total number of mast cells appearing in cutaneous, and subcutaneous tissues, and underlying abdominal musculature of immunized mice increased significantly compared with non-immunized mice. Mast cells from hookworm-infected mice showed evidence of membrane rupture and degranulation in contrast to the intact appearance of mast cells from uninfected mice. The degree of mast cell degranulation was greater in vaccinated and challenged mice when compared with non-immunized and infected mice. Similarly, eosinophilic infiltration was greatly enhanced after L3 infection. Tissues from vaccinated mice had a greater number of eosinophils than non-immunized mice after infection.

CONCLUSIONS

Mast cell alterations appearing earlier than tissue eosinophilic infiltration is major inflammatory response to Ancylostoma caninum (A. caninum) L3 infection in mice. These processes are more obvious in L3-vaccinated mice.

Caring attributes, professional self concept and technological influences in a sample of Registered Nurses in eleven countries

Caring, the theoretical foundation of nursing, is identified as one of the core values by Hospital Authorities world-wide to be actualised in clinical practice. Exactly how caring attributes relate to nurses' professional self image and quality nursing service in the context of a contemporary technological environment have yet to be operationalised. In total, 1957 Registered Nurses from 11 different countries were involved in the study which aimed to: develop an understanding of and compare the responses to items relating to caring, professional self concept and technological influences. To collect data an instrument containing 104 Likert items was administered to RNs working in general hospitals. The instrument contained sections which examined professional self concept, technological influences and caring attributes. Descriptive and inferential statistics revealed that many of the Asian nurses in the sample were younger, had less experience yet were more qualified than their 'western' colleagues. The mean scores for the caring attributes for nurses from the Philippines, Sweden and South Africa were significantly higher than those from China (Beijing), Korea, China (Hong Kong) and Scotland. The Korean sample demonstrated the lowest mean score for professional self concept while the New Zealand sample the highest. The Australian, Canadian, NZ, Scotland and Swedish samples were strongly of the opinion that the increase in technology has not brought about the any more spare time in nursing and generally had a more negative opinion about the influence of technology when compared to those from China (Beijing), Philippines, China (Hong Kong) and Singapore. The results are discussed in the light of the cultural differences in the sample and recommendations for future research are considered.

Alcohol consumption and alcohol-related problems: Chinese experience from six area samples, 1994

AIMS

To understand the drinking frequency, mean yearly volume of consumption and drinking-related problems in individuals living in six areas in China.

DESIGN AND MEASUREMENTS

By two-stage sampling, 23,513 community household residents (15-65 years old) were assessed with data collected by trained psychiatrists using structured questionnaires and DSM-III-R criteria.

FINDINGS

The male, female and total drinking rates were 84.1%, 29.3% and 59.5%, respectively. More than half of male drinkers and 90.0% of female drinkers used alcohol once a week or less. More than 16.1% of male drinkers and 2.5% of female drinkers drank once a day or more. The males reported a greater amount of alcohol consumed per session. The mean yearly volume of consumption of pure alcohol per year for all sample was 3.60 l; males consumed 18.6 times more alcohol than females. The rate of alcohol-related problems was higher in males than females. The male, female and total alcohol dependence point prevalence rates were 6.632%, 0.104% and 3.428%, respectively. Six-month incidence rates of acute intoxication were 5.162% 0.017% and 2.637%, respectively.

CONCLUSION

Drinking problems in China will continue to be a public health problem in the next century.

Folylpoly-gamma-glutamate synthetase: generation of isozymes and the role in one carbon metabolism and antifolate cytotoxicity

A single human gene encodes both mitochondrial and cytosolic isoforms of the enzyme. The major mRNA species in human cells encodes the mitochondrial isoform but alternate translation initiation at a downstream in-frame ATG also generates the cytosolic isoform. Cytosolic FPGS may also be generated by use of alternate transcription initiation start sites 3' to the start ATG of the mitochondrial FPGS. Three additional human FPGS mRNAs differing in exon 1 have been identified. One of these is a major species in HEP-G2 cells and other tissue culture cells, and can encode a protein lacking the first 8 amino acids of cytosolic FPGS. A protein of the predicted size is observed in coupled transcription/translation systems. However, expression of this protein in E. coli does not generate an active enzyme. Mutagenesis studies indicate that Tyr-3 of the missing N terminal residues is required for enzyme activity. The major cellular folate pools are in the cytosol and mitochondria and FPGS activity is normally distributed in both compartments. Mitochondrial FPGS activity is required for mitochondrial folate accumulation, and cells lacking this isozyme are auxotrophic for glycine. Overexpression of cytosolic FPGS does not complement the lack of mitochondrial activity. Cells expressing FPGS activity solely in the mitochondria are glycine prototrophs, but also possess cytosolic folylpolyglutamates and are prototrophic for thymidine and purines, products of cytosolic one carbon metabolism. Although cytosolic folylpolyglutamates cannot enter the mitochondrion, mitochondrial folylpolyglutamates are released intact into the cytosolic compartment. Cellular accumulation of some antifolates and their cytotoxic efficacy is highly responsive to the level of FPGS activity. Polyglutamylation of methotrexate (MTX) has little affect on its affinity for dihydrofolate reductase, its target enzyme, but does affect the cellular accumulation of the drug. The sensitivity of model cells, expressing a range of FPGS activities similar to that observed in leukemia blasts, to MTX varied over four orders of magnitude. MTX toxicity was dependent on cytosolic FPGS activity as this drug does not enter the mitochondria, and cells expressing very high levels of FPGS solely in the mitochondria were resistant to MTX. The cytotoxic efficacy of other folate antagonists that are transported into the mitochondria was enhanced by mitochondrial FPGS activity, even when their loci of inhibition was a cytosolic enzyme. Mitochondrial metabolism of these drugs increased cytosolic drug levels. Compartmentalization of antifolate metabolism has to be considered in evaluating mechanisms for increased drug cytotoxicity and for the development of acquired resistance to these agents.

Hypothesis: A recurrent, moderate activation fosters systemic autoimmunity--the apoptotic roles of TCR, IL-2 and Fas ligand

Studies of several gene knockout mice suggest an interesting association of a moderate T cell response with systemic autoimmune diseases. In addition, CD95 ligand (FasL) expression in some strains of these mice is impaired. Because FasL is critically involved in regulating peripheral tolerance, there may be a link between autoimmune diseases and a moderate T cell response that cannot activate the FasL gene. Here, we propose that there are two thresholds of T cell activation. When moderately stimulated, T cells can be activated to the low (1st) threshold, which permits the induction of CD40L, IL-2, IL-4, and other components that help the immune response. The high (2nd) activation threshold can only be achieved by a strong and concurrent stimulation through TCR and IL-2R. Once the high threshold is reached, FasL is produced to induce apoptosis of the activated T and B cells. In the absence of the FasL-mediated downregulation, the activated B cells become efficient antigen-presenting cells for self-antigens and excellent responders for T cell help. Such an exacerbating condition, induced by recurrent and moderate activation, favors the development of autoreactive T cells and autoantibody production. Evidence supporting this hypothesis and some predictions that can be tested are described.

[Direct chromosome analysis and FISH study of primary gastric cancer]

OBJECTIVE

To investigate chromosome aberrations and their role in the genesis and progression of primary gastric cancer.

METHODS

An improved, direct method of chromosome preparation from solid tumors was adopted for G-banding analysis followed by FISH on decolored G-banding chromosomes so that chromosome aberrations could be confirmed at DNA level.

RESULTS

A total of 28 primary gastric cancer specimens were studied. Case 1 and case 2 had simple chromosome numerical changes: 49, XY, +2, +8, +9 and 47, XX, +8, +20, respectively. All but case 1 and 2 had complicated chromosome abnormalities. Structural changes of frequent occurrence involved del(7q) (21/26), del(3p)(14/26), del(1p)(11/26) and del(17p)(10/26). The chromosome abnormalities could be simple or complicated. In the former, numerical changes involving 1 to 3 chromosomes could be observed. Trisomies 8 and 9 appeared to be a cytogenetic subgroup of primary gastric cancer. In the latter, del(7q) was the most consistent structural aberration. The 7q32-qter was the commonly lost segment.

CONCLUSION

Numerical and structural alterations of chromosomes are present in primary gastric cancer. Del(7q) is one of the structural changes characteristic of primary gastric cancer. In the 7q32-qter segment, a tumor suppressor gene probably exists and it may have close relation to the genesis and progression of gastric cancer.

Effect of Gasoline Contamination on the Permeation of Organic Liquids through Rubber Membranes

The effect of gasoline and oil contamination on the barrier properties of natural rubber, nitrile rubber and bromobutyl rubber have been experimentally studied for the following organic environmental contaminants: dichloromethane, acetone and toluene. Oil contamination has little effect on the subsequent transport of these organic penetrants. However, gasoline contamination alters the subsequent transport behavior of these organic penetrants, depending on the nature of the rubber and the contamination conditions. Nitrile rubber experiences minor effects, while natural rubber is severely affected. Penetrant breakthrough times as well as limiting diffusion coefficients increase with increasing temperature and/or contamination time.

Fossil preservation in the Neoproterozoic Doushantuo phosphorite Lagerstatte, South China

Phosphorites of the late Neoproterozoic Doushantuo Formation exposed in the vicinity of Weng'an, Guizhou Province, and Chadian, Shaanxi Province, South China, contain exceptionally well-preserved algal thalli, acritarchs, and globular microfossils interpreted as animal embryos. Combined optical microscopic and SEM observations provide insights into the taphonomy of phosphatized fossils. Algal cells and tissues are variably resistant to decay, and within preserved populations permineralization began at varying stages of degradation. In consequence, there is a spectrum of quality in cellular preservation. Algal cell walls, acritarch vesicles, and embryo envelopes are commonly encrusted by an isopachous rim of apatite, with cell interiors filled by collophane and later diagenetic dolomite. In contrast, blastomere surfaces of animal embryos are encrusted primarily by minute phosphatic spherules and filaments, possibly reflecting an immediately postmortem infestation of bacteria that provided nucleation sites for phosphate crystal growth. Thus, the same processes that gave rise to Phanerozoic phosphatized Lagerstatten--phosphatic encrustation, and impregnation, probably mediated by microbial activity--effected soft-tissue preservation in the Doushantuo Lagerstatte. It remains unclear how phosphatic ions and organic macromolecules interact at the molecular level and to what extent specific microbial metabolisms or microenvironmental conditions control the phosphatization of soft tissues. New observations of phosphatized Doushantuo fossils include: a second locality (Chadian) for Wengania globosa, interpreted as an algal thallus and previously known only from Weng'an; microtunnels in Weng'an phosphorites interpreted as pyrite trails; and new taxa described from Weng'an: Meghystrichosphaeridium reticulatum (acritarch), Sarcinophycus radiatus (algal thallus), and one unnamed problematic form.

[Direct determination of purine bases in tea by reversed-phase high performance liquid chromatography]

A reversed-phase high performance liquid chromatographic(RP-HPLC) method for the direct determination of three purine bases(theobromin, theophyllin and caffeine) in tea was developed. An ODS column with Zorbax SB-C18(4.6 mm i.d. x 250 mm, 5 microns) was employed. The aqueous solution of methanol containing 0.05% of acetic acid and 0.25% of N,N-dimethylformamide(DMF) was used as eluent with a flow rate of 0.8 mL/min. In this method, the aqueous extract of tea can be injected into HPLC directly, but in current HPLC methods for purine bases the coexisted tea polyphenols must be pre-separated. The three purine bases in tea were separated without any interference from the coexisted tea polyphenols. This method is simple (without any special sample pretreatment) and sensitive with detection limits (S/N = 3) of 0.7, 0.9 and 1.8 mg/L for theobromin, theophyllin and caffeine respectively. The linear range of the calibration curve of peak area for the three purine bases were from 6 mg/L to 1,000 mg/L with a correlation coefficient (r) of 0.998-0.999.

Association of a cellular 21-kDa transmembrane protein (VAP21) with enveloped viruses

We reported previously that the rabies virions contained a 21-kDa cellular transmembrane protein (referred to as VAP21) as a minor component (Sagara, J. et al, Microbiol. Immunol. 41(12): 947-955, 1997). In this study, we further examined the possible interactions of VAP21 with other enveloped viruses, including the vesicular stomatitis virus (VSV; negative-stranded RNA virus), Sindbis virus (positive-stranded RNA virus) and herpes simplex virus type 1 (HSV-1; double-stranded DNA virus). An immunoblot analysis demonstrated that all of these enveloped viruses contained VAP21 in the virion as a minor component. Immunoprecipitation studies suggested that VAP21 was associated with certain viral proteins in the cell, such as the matrix (M) protein of VSV, a capsid protein of Sindbis virus, and at least a capsid protein (VP5) of HSV-1. The association was disrupted by treatment with 0.5% sodium dodecyl sulfate, but resistant to the treatment with 1% NP-40 plus 1% deoxycholate. These results suggest that: 1) VAP21 is not primarily associated with the viral transmembrane glycoprotein but rather with the internal viral protein, and, 2) this association would cause the efficient incorporation of VAP21 into the virion.

Rapid, direct determination of polyphenols in tea by reversed-phase column liquid chromatography

Column liquid chromatography on a C18-bonded silica column with water-methanol-acetic acid as eluent was used to determine polyphenols and caffeine in tea. Without any pretreatment, catechin, epicatechin gallate, epigallocatechin gallate, epigallocatechin, epicatechin and caffeine were separated successfully within 15 min. The detection limits (S/N = 3) of polyphenols studied were 1.8-24 mg/l at a detection wavelength 270 nm. The linear range of the peak area calibration curves for the analytes were over two orders of magnitude with a correlation coefficient of 0.996-0.999. Using this method, some Chinese tea samples were analyzed with a good reproducibility (RSD are below 5%).

[The correlation between t(14;18) chromosomal translocation and hepatocarcinoma]

OBJECTIVE

To study the correlation between t(14;18) chromosomal translocation and the occurrence of hepatocarcinoma.

METHODS

bcl-2/JH fusion gene in 54 cases of hepatocarcinoma including 40 cases of hepatocellular carcinoma(HCC) and 14 cases of cholangicellular carcinoma (CCC) were investigated using seminested in situ PCR.

RESULTS

Bcl-2/JH fusion gene was present in 25% (10/40) HCC and negative in CCC.

CONCLUSION

These findings indicated that t(14;18) chromosomal translocation might play a role in the pathogenesis of HCC but seemed to bear no relation with CCC. mbr and mcr are the two important breakpoints of bcl-2 gene in HCC.

[Depressive disorders among outpatients in general hospitals]

OBJECTIVE

To investigate the prevalence, recognition and treatment of depressive disorders among outpatients in general hospitals.

METHODS

26,969 outpatients of general hospitals 15 countries were interviewed by GHQ-28, CIDI and physician interview scale in two-stage case identification process. In Shanghai, 583 patients were interviewed by all scales, among them men and women were in 38.0% and 62.0% respectively.

RESULTS

Among all the psychological problems, the prevalence of depressive disorders was listed as the first one. The prevalence of major depression and dysthymia in the whole sample was 10.4% and 2.1% respectively and in Shanghai it was 4.0% and 0.6% respectively. The recognized rate of depressive disorders by physician in Shanghai was 21%, which was much lower than 55.6%--the medium among the fifteen countries. The treatment of depressive disorders by physician was inadequate. None of antidepressants was prescribed by any of physician for the recognized depressive disorders in Shanghai.

CONCLUSIONS

Depressive disorders are the most common psychological problems in the outpatients of general hospitals, but they are under-recognized and inadequately treated in general hospitals. Reeducation of physician on mental health knowledge must be emphasized by the whole society.

[Effects of Kupffer cells stimulated by triglyceride and very low-density lipoprotein on proliferation of rat hepatic stellate cells]

OBJECTIVE

To study the effects of Kupffer cell-conditioned medium (KCCM) derived from triglyceride and very low-density lipoprotein (VLDL) treatment on proliferation of rat hepatic stellate cells (HSC).

METHODS

HSC and Kupffer cells were isolated from liver of Wistar rats by in situ perfusion with pronase and collagenase and density gradient centrifugation with Nycodenz and then cultured. KCCM was prepared and MTT colorimetric assay was used to detect HSC proliferation.

RESULTS

HSC and Kupffer cells were isolated successfully with high purity. 12.5 mg/L of triglyceride and 25 - 100 mg/L of VLDL promoted HSC proliferation (P < 0.05 or 0.01); KCCM + triglyceride and KCCM + VLDL might promote HSC proliferation as compared with a control group (P < 0.01). There was no significant difference between KCCM + triglyceride and KCCM + VLDL (P > 0.05).

CONCLUSION

The technique for isolation of HSC and Kupffer cells described here is simple and reliable. Triglyceride, VLDL and KCCM stimulated by them may promote HSC proliferation and be associated with fatty liver and hepatic fibrogenesis.

Effects of Kupffer cells stimulated by triglyceride and very low-density lipoprotein on proliferation of rat hepatic stellate cells

OBJECTIVE

To study the effects of triglyceride, very low-density lipoprotein (VLDL), and Kupffer cell-conditioned medium (KCCM) derived from triglyceride and VLDL treatment on proliferation of rat hepatic stellate cells (HSC).

METHODS

HSC and Kupffer cells were isolated and cultured from liver of Wistar rats by in situ perfusion with proteinase and collagenase, and density gradient centrifugation with Nycodenz; HSC and Kupffer cells were identified by immunohistochemistry, endocytosis, and ultrastructure, etc. Kupffer cells were incubated with triglyceride (25 micrograms/ml) and VLDL (25 micrograms/ml) for 24 hours, KCCM were prepared, and MTT colorimetric assay was detected for HSC proliferation.

RESULTS

HSC proliferation was 0.1894 +/- 0.0316 (12.5 micrograms/ml), 0.1637 +/- 0.0243 (25 micrograms/ml), 0.1450 +/- 0.0264 (50 micrograms/ml), 0.1212 +/- 0.0275 (100 micrograms/ml), 0.1226 +/- 0.0138 (200 micrograms/ml) and 0.0990 +/- 0.0163 (400 micrograms/ml) in the presence of triglyceride and was 0.1583 +/- 0.0314 (6.25 micrograms/ml), 0.1642 +/- 0.0269 (12.5 micrograms/ml), 0.1834 +/- 0.0498 (25 micrograms/ml), 0.1964 +/- 0.0287 (50 micrograms/ml) and 0.2202 +/- 0.0284 (100 micrograms/ml) in presence of VLDL, respectively. Compared with the control, HSC proliferation at 400 micrograms/ml of triglyceride was lower (P < 0.01), but at 12.5 micrograms/ml of triglyceride and 25, 50, 100 micrograms/ml of VLDL higher (P < 0.05 or 0.01); HSC proliferation was 0.1569 +/- 0.0144, 0.1924 +/- 0.0113 and 0.1871 +/- 0.0116 in the presence of KCCM, KCCM + triglyceride and KCCM + VLDL, respectively. Compared with the control and KCCM, KCCM + triglyceride and KCCM + VLDL might promote HSC proliferation (P < 0.01); there was no statistical significance between KCCM + triglyceride and KCCM + VLDL (P > 0.05); KCCM was greater in HSC proliferation than the control, but there was no significant change (P > 0.05).

CONCLUSIONS

Triglyceride, VLDL, and KCCM stimulated by triglyceride and VLDL might promote HSC proliferation and be associated with fatty liver and hepatic fibrogenesis.

Enzyme-linked immunoelectrotransfer blotting analysis of human serologic responses to infective hookworm larval antigen

OBJECTIVE

To explore the possibility of using specific antigens for immunodiagnosis of hookworm disease in endemic area.

METHOD

Infective third-stage larvae of the canine hookworm, Ancylostoma caninum (A. caninum), were prepared as the source of antigen. Enzyme-linked immunoelectrotransfer blotting (EITB) was employed as an immunodiagnostic method.

RESULTS

Two immunodominant bands of hookworm antigens (42 kDa and 55 kDa) were recognized by the sera of hookworm-infected patients (serum dilution 1:200; antigen centrifuged at 36,000 r/m for 20 minutes, but not by sera from negative controls.

CONCLUSION

The 42 kDa and 55 kDa A. caninum antigens might be the specific antigens that could be used for immunodiagnosis of hookworm disease in endemic area.

The functional role of CrkII in actin cytoskeleton organization and mitogenesis

Crk is a member of a family of adapter proteins predominantly composed of Src homology 2 and 3 domains, whose role in signaling pathways is presently unclear. Using an in situ electroporation system which permits the introduction of glutathione S-transferase (GST) fusion proteins into cells, we found that c-CrkII bound to p130(cas), but not to paxillin in serum-starved rat-1 fibroblasts overexpressing the human insulin receptor (HIRc cells) in vivo. 17 nM insulin stimulation dissociated the binding of c-CrkII to p130(cas), whereas 13 nM insulin-like growth factor-I, 16 nM epidermal growth factor (EGF), and 10% serum each showed little or no effect. We found that stress fiber formation is consistent with a change in the p130(cas).c-CrkII interactions before and after growth factor stimulation. Microinjection of either GST-Crk-SH2 or -Crk-(N)SH3 domains, or anti-Crk antibody each inhibited stress fiber formation before and after insulin-like growth factor-I, EGF, and serum stimulation. Insulin stimulation by itself caused stress fiber breakdown and there was no additive effect of microinjection. Microinjection of anti-p130(cas) antibody also blocked stress fiber formation in quiescent cells. Microinjection of the Crk-inhibitory reagents also inhibited DNA synthesis after insulin-like growth factor-I, EGF, and serum stimulation, but not after insulin. These data suggest that the complex containing p130(cas).c-CrkII may play a crucial role in actin cytoskeleton organization and in anchorage-dependent DNA synthesis.

Taoistic cognitive psychotherapy for neurotic patients: a preliminary clinical trial

Taoistic cognitive psychotherapy is a cognitive therapy based on Taostic philosophy of life and health. The present preliminary study aims to test clinical significance of the Taoistic cognitive psychotherapy, indicates that type A behavior patterns distorted values and psychopathologies can be improved after a short period (4 weeks) of Taoistic cognitive psychotherapy. The theoretical basis of this psychotherapy is also briefly introduced.

Psychoactive substance use in three sites in China: gender differences and related factors

One year prevalence rates for psychoactive substance use are reported based on community surveys performed in three sites in China: Hunan, Heilongjiang and Jiangsu. The data were gathered on more than 14,000 respondents (15-65 years old). The drinking rates were from 58.3 to 82.6% for men and from 16.3 to 31.4% for women. Smoking rates range from 64.9 to 68.1% for men and from 0.1 to 20.5% for women. Most drinkers were light users and most smokers were heavy users. Illicit drug use was observed at Hunan. Regarding frequency and quantity of psychoactive substance use, women are lighter consumers than their male counterparts except for use of minor tranquilizers and analgesics. The psychosocial factors related to drinking and smoking were also investigated in this study.

Congenital mesoblastic nephroma t(12;15) is associated with ETV6-NTRK3 gene fusion: cytogenetic and molecular relationship to congenital (infantile) fibrosarcoma

Morphological, cytogenetic, and biological evidence supports a relationship between congenital (infantile) fibrosarcoma (CFS) and congenital mesoblastic nephroma (CMN). These tumors have a very similar histological appearance, and they are both associated with polysomies for chromosomes 8, 11, 17, and 20. Recently, CFS was shown to contain a novel t(12; 15)(p13;q25) translocation resulting in ETV6-NTRK3 gene fusion. The aims of this study were to determine whether congenital mesoblastic nephroma contains the t(12;15)(p13;q25) translocation and ETV6-NTRK3 gene fusion and whether ETV6-NTRK3 fusions, in CMN and CFS, antedate acquisition of nonrandom chromosome polysomies. To address these aims, we evaluated 1) ETV6-NTRK3 fusion transcripts by reverse transcriptase polymerase chain reaction and sequence analysis, 2) genomic ETV6-region chromosomal rearrangement by fluorescence in situ hybridization, and 3) chromosomal polysomies by karyotyping and fluorescence in situ hybridization. We report ETV6-NTRK3 fusion transcripts and/or ETV6-region rearrangement in five of six CMNs and in five of five CFSs. The ETV6-NTRK3 fusion transcripts and/or ETV-region chromosome rearrangements were demonstrated in two CMNs and one CFS that lacked chromosome polysomies. These findings demonstrate that t(12;15) translocation, and the associated ETV6-NTRK3 fusion, can antedate acquisition of chromosome polysomies in CMN and CFS. CMN and CFS are pathogenetically related, and it is likely that they represent a single neoplastic entity, arising in either renal or soft tissue locations.

Subtracted, unique-sequence, in situ hybridization: experimental and diagnostic applications

Nonrandom chromosomal aberrations, particularly in cancer, identify pathogenic biological pathways and, in some cases, have clinical relevance as diagnostic or prognostic markers. Fluorescence and colorimetric in situ hybridization methods facilitate identification of numerical and structural chromosome abnormalities. We report the development of robust, unique-sequence in situ hybridization probes that have several novel features: 1) they are constructed from multimegabase contigs of yeast artificial chromosome (YAC) clones; 2) they are in the form of adapter-ligated, short-fragment, DNA libraries that may be amplified by polymerase chain reaction; and 3) they have had repetitive sequences (eg, Alu and LINE elements) quantitatively removed by subtractive hybridization. These subtracted probes are labeled conveniently, and the fluorescence or colorimetric detection signals are extremely bright. Moreover, they constitute a stable resource that may be amplified through at least four rounds of polymerase chain reaction without diminishing signal intensity. We demonstrate applications of subtracted probes for the MYC and EWS oncogene regions, including 1) characterization of a novel EWS-region translocation in Ewing's sarcoma, 2) identification of chromosomal translocations in paraffin sections, and 3) identification of chromosomal translocations by conventional bright-field microscopy.

Supersensitivity to serotonin- and histamine-induced arterial contraction following ovariectomy

The modulating role of estrogens and ovariectomy on coronary artery and thoracic aortic rings was examined in female rabbits. Three treatment groups were studied: (1) control, (2) ovariectomy, and (3) ovariectomy + 17beta-estradiol acetate (40 microg/kg per day, i.m. for 7 days). Coronary artery reactivity was studied in the isolated retrogradely perfused heart. Aortic reactivity was studied using endothelium intact and denuded aortic rings. Concentration-response curves were performed to serotonin (5-HT) and histamine. A 21-fold, a 4.7-fold, and a 5.2-fold increase in sensitivity to 5-HT-induced contraction were observed in the ovariectomy group compared to the control group for coronary artery, intact aortic, and denuded aortic preparations, respectively (P < 0.05 for each comparison). Similarly, 34-fold, 4.9-fold, and 5.0-fold increases in sensitivity to histamine-induced contraction were observed in the ovariectomy group compared to control group for coronary artery, intact aortic, and denuded aortic preparations, respectively (P < 0.05 for each comparison). 17beta-Estradiol administration reversed the supersensitivity to serotonin- and histamine-induced vascular contraction observed following ovariectomy. No differences in EC50 or maximal contraction were noted between control and ovariectomy + estrogen groups. Baseline nitric oxide release and maximal 5-HT- and histamine-induced nitric oxide release from the perfused heart were decreased (P < 0.05) in ovariectomy rabbits compared to control and ovariectomy + estrogen treatment groups. The data demonstrate that (1) reduced autacoid-induced nitrous oxide release following ovariectomy and (2) direct effects upon the vascular smooth muscle contractility, which are probably mediated by altered receptor sensitivity by ovariectomy and estrogen replacement therapy. The information obtained from this study provides additional information regarding possible beneficial actions of estrogen replacement therapy in post-menopausal women.

[Protease inhibitory activities of nasal secretion on house dust mite allergen]

OBJECTIVE

To elucidate the interaction of protease inhibitors and house dust mite allergen in vitro.

METHODS

Nasal secretion was collected by suction from patients with house dust mite nasal allergy, diluted immediately with PBS pH 7.0, mixed with vortex for 10 minutes, and then centrifuged at 2,000 g for 10 minutes. The supernatant was kept at -80 degrees C for use. Synthetic low molecular weight fluorogenic peptide substrates were applied to evaluate protease activities. Crude mite extract and other proteases were used, each of them was preincubated in the presence or absence of nasal fluid or other protease inhibitors at 37 degrees C for 30 minutes. The intensity of fluorescence of aminomethylcoumarin released from the cleaved substrate was measured.

RESULTS

Nasal fluid exhibited mild trypsin-like and other protease activities. It inhibited the activities of trypsin and trypsin-like serine proteases and papain-like cysteine proteases in crude mite extract in a dose-dependent manner.

CONCLUSIONS

Nasal fluid possibly plays a role in inhibiting penetration of allergen into the nasal mucosa by producing protease inhibitor-protease complex in the nasal mucus layer of patients with mite allergy.

Effects of limb perturbation on surface recorded nerve action potentials

The field action potentials are a convolution of source strength and the propagating-point source responses (PPSRs). Surface-recorded peripheral nerve potentials are strongly influenced by the volume-conductor properties of the limb. In this paper the PPSRs are solved based on finite-element formulation, which allows solutions to forward volume-conductor problems involving curved nerves in arbitrarily shaped, inhomogeneous, anisotropic limbs. Effects of limb perturbation on surface-recorded nerve action potentials are simulated based on circular and elliptic cylinders with a uniform cross-section consisting of multiple inhomogeneous and anisotropic regions (fat, muscles, and bone layers). The simulations show that a simple homogeneous model is adequate only for a very superficial nerve that lies completely in the subcutaneous fat layer. Deeper nerves that lie on or within the muscle require a multiple-layer model that takes both the muscle and the fat into account. The cross section only needs to be modeled accurately between the recording site and the nerve location. A circular limb model is adequate for clinical recordings. However, an accurate knowledge of the nerve path is essential for accurate modeling of the action potentials, in both needle and surface recordings.

[Significance of bcl-2 gene breaking and bcl-2 protein expression in nasopharyngeal carcinoma]

In order to study the relationship between bcl-2 gene and nasopharyngeal carcinoma. The two hot breakpoints of bcl-2 gene and bcl-2 protein expression were examined by in situ hybridization and immunohistochemistry technique in 41 nasopharyngeal carcinoma(NPC) tissues. bcl-2 gene breakpoint were found in 4 cases of NPC(positive rate 9.8%). 34 cases of NPC expressed bcl-2 protein, the positive incidence was 82.9%. No statistically significant differences was found in histological grades. All benign lesions were negative for bcl-2 gene breaking and bcl-2 protein expression. There was no corresponding relation between bcl-2 protein expression and bcl-2 gene breaking. The results implicated that bcl-2 gene breaking may not play an important role in the pathogenesis of NPC. It also suggested that overexpression of bcl-2 protein may involved in carcinogenesis of nasopharyngeal epithelium.

Correlation between DNA methylation and pathological changes in human hepatocellular carcinoma

BACKGROUND/AIMS

This study was undertaken to obtain information at the molecular level on the possible mechanism of human hepatocarcinogenesis and also to provide a clue for further study.

METHODOLOGY

We examined the methylation patterns of c-myc and c-N-ras oncogenes, which are most closely related to HCC, by using the Southern blot technique and HpaII/MspI restriction enzymes. In addition, we measured the level of global DNA methylation in cancerous and paracancerous tissues of HCC by incubating DNA with 3H-S-adenosylmethionine (3H-SAM) in the presence of methylase. The measured global level of DNA methylation was compared with pathological changes of the liver. The methylation patterns of oncogenes as well as the levels of global DNA methylation were compared with pathological changes.

RESULTS

The results showed that the hypomethylation rates of c-myc and c-N-ras oncogenes were 30% and 61% respectively in human hepatocellular carcinoma, coinciding with a decreased level of global DNA methylation. DNA hypomethylation was highly significant in cases with a tendency of tumor infiltration or metastasis.

CONCLUSIONS

It is concluded that abnormal DNA methylation plays an important role in the process of hepatocellular carcinogenesis. DNA methylation level is closely correlated with the biological characteristic of liver cancer, the lower the level of DNA methylation, the stronger the infiltration and metastatic capacity.