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Yi Chen

Publications and source records attributed to Yi Chen.

At least 181 records · Page 10Linked to original sources
PubMed2003

Fast enantioseparation of arylglycine amides by capillary electrophoresis with highly sulfated-beta-cyclodextrin as a chiral selector.

Nine racemic arylglycine amides were synthesized and successfully enantioseparated by capillary electrophoresis (CE) using highly sulfated beta-cyclodextrin (HS-beta-CD) as a chiral selector. Baseline enantioseparation of the analytes was obtained around neutral pH but not in the acidic conditions that are commonly used. HS-beta-CD content, buffer pH, type and concentration, and organic modifier concentration were studied and optimized for fast and efficient separation. A chiral CE separation system composed of 1.5% (w/v) HS-beta-CD, 0 to 10% (v/v) methanol and 20 mM 3-(N-morpholino)propanesulfonic acid at pH 6.5 was shown suitable for baseline enantioseparation of the mentioned amides within 6 min, including simultaneous enantioseparation of three positional isomer series (methyl-, methoxyl or chloro-substituted). By using this system, D-enantiomers migrated ahead of the L-enantiomers and the enantiomeric resolution order of arylglycine amides was more or less parallel to the pK(a), order of the analytes.

Amides↗
PubMed2003

Cardioprotection through a PKC-dependent decrease in myofilament ATPase.

Activation of myocardial kappa-opioid receptor-protein kinase C (PKC) pathways may improve postischemic contractile function through a myofilament reduction in ATP utilization. To test this, we first examined the effects of PKC inhibitors on kappa-opioid receptor-dependent cardioprotection. The kappa-opioid receptor agonist U50,488H (U50) increased postischemic left ventricular developed pressure and reduced postischemic end-diastolic pressure compared with controls. PKC inhibitors abolished the cardioprotective effects of U50. To determine whether kappa-opioid-PKC-dependent decreases in Ca2+-dependent actomyosin Mg2+-ATPase could account for cardioprotection, we subjected hearts to three separate actomyosin ATPase-lowering protocols. We observed that moderate decreases in myofibrillar ATPase were equally cardioprotective as kappa-opioid receptor stimulation. Immunoblot analysis and confocal microscopy revealed a kappa-opioid-induced increase in myofilament-associated PKC-epsilon, and myofibrillar Ca2+-independent PKC activity was increased after kappa-opioid stimulation. This PKC-myofilament association led to an increase in troponin I and C-protein phosphorylation. Thus we propose PKC-epsilon activation and translocation to the myofilaments causes a decrease in actomyosin ATPase, which contributes to the kappa-opioid receptor-dependent cardioprotective mechanism.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed2003

Laminin-10 is crucial for hair morphogenesis.

The role of the extracellular matrix in cutaneous morphogenesis is poorly understood. Here, we describe the essential role of laminin-10 (alpha5beta1gamma1) in hair follicle development. Laminin-10 was present in the basement membrane of elongating hair germs, when other laminins were downregulated, suggesting a role for laminin-10 in hair development. Treatment of human scalp xenografts with antibodies to laminin-10, or its receptor beta1 integrin, produced alopecia. E16.5 Lama5 -/- mouse skin, lacking laminin-10, contained fewer hair germs compared with controls, and after transplantation, Lama5 -/- skin showed a failure of hair germ elongation followed by complete hair follicle regression. Lama5 -/- skin showed defective basement membrane assembly, without measurable increases in anoikis. Instead, Lama5 -/- skin showed decreased expression of early hair markers including sonic hedgehog and Gli1, implicating laminin-10 in developmental signaling. Intriguingly, treatment of Lama5 -/- skin with purified laminin-10 corrected basement membrane defects and restored hair follicle development. We conclude that laminin-10 is required for hair follicle development and report the first use of exogenous protein to correct a cutaneous developmental defect.

Alopecia↗
PubMed2003

Determination of carbohydrates as their 3-aminophthalhydrazide derivatives by capillary zone electrophoresis with on-line chemiluminescence detection.

A method based on pre-capillary derivatization with luminol (3-aminophthalhydrazide) for carbohydrate analysis using capillary electrophoresis with on-line chemiluminescence (CL) detection was developed. The derivatives of seven monosaccharides were separated and detected by using 200 mM borate buffer containing 100 mM hydrogen peroxide at pH 10.0 as separation electrolyte and 25 mM hexacyanoferrate in 3 M sodium hydroxide solution as post-capillary chemiluminescence reagent with separation efficiencies ranging from 160,000 to 231,000 plates per metre. The minimum amount of carbohydrate derivatized was 2 pmol (corresponding to the concentration of 2 microM). The method also provided a linear response for glucose in the concentration range of 0.1-250 microM with a mass detection limit of 420 amol or a concentration detection limit of 0.1 microM. Preliminary work using the CE-CL format to determine glucose in a rat brain microdialysis sample is presented as a typical case.

Carbohydrates↗
PubMed2003

KappaB-Ras binds to the unique insert within the ankyrin repeat domain of IkappaBbeta and regulates cytoplasmic retention of IkappaBbeta x NF-kappaB complexes.

The IkappaBalpha and IkappaBbeta proteins inhibit the transcriptional potential of active NF-kappaB dimers through stable complex formation. It has been shown that inactive IkappaBalpha x NF-kappaB complexes shuttle in and out of the nucleus, whereas IkappaBbeta x NF-kappaB complexes are retained exclusively in the cytoplasm of resting cells. The biochemical mechanism underlying this functional difference and its consequences are unknown. Although the two IkappaB proteins are significantly homologous, IkappaBbeta contains a unique 47-amino acid insertion of unknown function within its ankyrin repeat domain. In this study, we assess the role of the IkappaBbeta insert in regulating cytoplasmic retention of IkappaBbeta.NF-kappaB complexes. Deletion of the IkappaBbeta insert renders IkappaBbeta x NF-kappaB complexes capable of shuttling between the nucleus and cytoplasm, similar to IkappaBalpha x NF-kappaB complexes. A small Ras-like G-protein, kappaB-Ras, participates with the IkappaBbeta insert to effectively mask the NF-kappaB nuclear localization potential. Similarly, a complex between NF-kappaB and a mutant IkappaBbeta protein containing four serine to alanine mutations within its C-terminal proline, glutamic acid, serine, and threonine-rich sequence exhibits nucleocytoplasmic shuttling. This suggests a phosphorylation state-dependent role for the C-terminal proline, glutamic acid, serine, and threonine-rich sequence of IkappaBbeta in proper localization of IkappaBbeta x NF-kappaB complexes. These results are consistent with structural studies, which predicted that binary IkappaBbeta x NF-kappaB complexes should be capable of nuclear translocation, and with previous observations that hypophosphorylated IkappaBbeta.NF-kappaB complexes can reside in the nucleus.

Animals↗
PubMed2003

Age-related functional effects linked to phosphatase activity in ventricular myocytes.

Conflicting reports exist regarding the influence of beta-adrenergic stimulation on the maximum velocity of shortening (Vmax) in ventricular myocytes. This may be due to an unrecognized effect of maturation. In the present study, the effects of beta-adrenergic receptor stimulation on myocytes from hearts of juvenile nonbred and young adult retired breeder female rats were compared. Ventricular myocytes from young adults had a beta-adrenergic-dependent increase in Vmax and Ca2+-dependent actomyosin ATPase that was not observed in myocytes from juveniles. Myocytes from young adults had both an increase in beta-myosin heavy chain (MHC) and higher basal serine/threonine phosphatase activity compared with juvenile rats. Additional studies established moderate increases in beta-MHC induced by hypothyroidism do not confer myocardial beta-adrenergic responsiveness, whereas inhibition of the higher phosphatase activity in myocytes from young adults blocks the age-dependent, beta-adrenergic-induced increase in cross-bridge cycling rates. We propose that the higher phosphatase activity of myocytes from young adults compared with juveniles allows for a greater functional response of the myocardium to beta-adrenergic stimulation.

Actin Cytoskeleton↗
PubMed2003

Interleukin-23 rather than interleukin-12 is the critical cytokine for autoimmune inflammation of the brain.

Interleukin-12 (IL-12) is a heterodimeric molecule composed of p35 and p40 subunits. Analyses in vitro have defined IL-12 as an important factor for the differentiation of naive T cells into T-helper type 1 CD4+ lymphocytes secreting interferon-gamma (refs 1, 2). Similarly, numerous studies have concluded that IL-12 is essential for T-cell-dependent immune and inflammatory responses in vivo, primarily through the use of IL-12 p40 gene-targeted mice and neutralizing antibodies against p40. The cytokine IL-23, which comprises the p40 subunit of IL-12 but a different p19 subunit, is produced predominantly by macrophages and dendritic cells, and shows activity on memory T cells. Evidence from studies of IL-23 receptor expression and IL-23 overexpression in transgenic mice suggest, however, that IL-23 may also affect macrophage function directly. Here we show, by using gene-targeted mice lacking only IL-23 and cytokine replacement studies, that the perceived central role for IL-12 in autoimmune inflammation, specifically in the brain, has been misinterpreted and that IL-23, and not IL-12, is the critical factor in this response. In addition, we show that IL-23, unlike IL-12, acts more broadly as an end-stage effector cytokine through direct actions on macrophages.

Animals↗
PubMed2003

Corpus callosum: musician and gender effects.

Previously we found that musicians have significantly larger anterior corpus callosum (CC). In the current study, we intended to replicate and extend our previous results using a new and larger sample of gender-matched subjects (56 right-handed professional musicians and 56 age- and handedness-matched controls). We found a significant gender x musicianship interaction for anterior and posterior CC size; male musicians had a larger anterior CC than non-musicians, while females did not show a significant effect of musicianship. The lack of a significant effect in females may be due to a tendency for a more symmetric brain organization and a disproportionately high representation of absolute pitch (AP) musicians among females. Although a direct causal effect between musicianship and alterations in the midsagittal CC size cannot be established, it is likely that the early commencement and continuous practice of bimanual motor training serves as an external trigger that can influence midsagittal CC size through changes in the actual callosal fiber composition and in the degree of myelinization, which will have implications for interhemispheric connectivity.

Adolescent↗
PubMed2003

A study of thoria on the surface of gamma-Al2O3.

The dispersion of thoria on the surface of gamma-Al2O3 and the surface properties of ThO2/gamma-Al2O3 samples, as well as the influence of the loading amount of thoria on the reduction behavior of copper oxide species, have been studied using XRD, XPS, FTIR, and TPR. The results indicate that the dispersion capacity of thoria, like that of ceria, is much lower than for two other tetravalent metal oxides, zirconia and titania, and the surface adsorption amount of the carbonyl compound and H2O slightly increases with increasing thoria loading. The different thoria loadings can influence the reduction behavior of the dispersed copper oxide by comparing the TPR results of CuO/ThO2/gamma-Al2O3 samples. In addition, the lower dispersion capacities of thoria and ceria on gamma-Al2O3 are tentatively discussed by considering the structural stability of the two oxides.

Journal Article↗
PubMed2003

Mediastinal and neck hematoma after cardiac catheterization.

Vascular complications after cardiac catheterization are rare and usually occur at the access sites. However, vessels along the tract of the catheter can also be injured, causing bleeding and hematoma formation. We present a 57-year-old male who underwent cardiac catheterization via the radial approach, later developing neck and mediastinal hematoma, which was managed conservatively. This complication has only been reported once in the English literature.

Cardiac Catheterization↗
PubMed2003

Critical factors for reproducible capillary electrophoresis of Escherichia coli cells.

Sharp peaks of Escherichia coli JM 109 (up to 1 300 000 theoretical plates) were recorded with either extremely diluted (< 5 mM) or extremely concentrated (ca. 150 mM) Tris-borate (TB) running buffers. However, under the conditions of yielding sharp peaks, migration time of E. coli was irreproducible. Critial factors influencing reproducibility were found to include bacterial growth phase, storage condition, cell pretreatment before injection, and concentration of running buffer. Buffer concentrations in the range of 20-100 mM TB were essential for reproducibility. E. coli JM 109 was shown to be sensitive to ultrasonification. Bacterial growth and storage conditions could be monitored by CE, with results comparable to those obtained with optical methods.

Bacteriological Techniques↗
PubMed2003

Comparison of wild-type and class I integrase mutant-FIV vectors in retina demonstrates sustained expression of integrated transgenes in retinal pigment epithelium.

BACKGROUND: In neonatal and adult rodent retina, substantial lentiviral vector expression has been detected primarily in retinal pigment epithelium (RPE), except in very young animals (2-5 days post-natal). In non-retinal tissues, studies of lentiviral vectors have utilized various controls. Among the most stringent are class I integrase mutants, which selectively block the integration reaction while leaving all other gag/pol-encoded functions intact. For HIV-1 vectors injected into brain, these have been used to simultaneously control for pseudotransduction and verify that long-term expression requires integration. Such experiments compare particles that differ only in a single amino acid within a single enzyme that forms a very small molar fraction of the virion. Class I integrase mutants have not been described for feline immunodeficiency virus (FIV) integrase, or tested in the eye for any lentiviral vector. METHODS: We compared subretinally and intravitreally injected FIV vectors and followed animals for up to 7 months, a duration that exceeds prior studies. We also compared the wild-type (WT) vector with one incorporating a single class I amino acid mutation in FIV integrase (D66V). A mock vector (packaging construct absent) was an alternative control. All vectors were vesicular stomatitis virus glycoprotein G (VSV-G)-pseudotyped and were injected on day 7 of life. One group of animals received either subretinal or intravitreal injections of WT vector in the right eyes. Control left eyes were injected with mock vector. These animals were sacrificed at 2 or 7 days post-injection. A second group received subretinal injections of either WT vector or equivalent D66V vector (reverse transcriptase-normalized to WT), and were analyzed after 2, 3 and 7 months. All eyes were scored for marker gene (beta-galactosidase) expression by an observer blinded to vector assignments. RESULTS: Subretinal FIV vector injections were much more effective than intravitreal injections. The RPE was the principal retinal layer transduced by the WT vector, and at least 50% of the area of the retina expressed the marker gene at 3 and 7 months. Occasional cells in inner retinal layers also expressed beta-galactosidase at these time points. The sustained retinal expression produced by subretinally injected vector was blocked by the D66V mutation. CONCLUSIONS: These results show that class I integrase mutant FIV vectors are useful control vectors, and that VSV-G-pseudotyped FIV vectors produce extensive retinal expression for at least 215 days, the longest duration yet reported for lentiviral vectors in retina. Transgene expression is mostly restricted to RPE after post-natal day 7 in rats, suggesting that FIV vectors could be used to target RPE for gene therapy.

Age Factors↗
PubMed2003

An intramolecular benzyl rearrangement of 1-(N-benzyloxycarbonylamino)alkylphosphonate diesters under electrospray ionization conditions.

The mass spectrometric behavior of eleven 1-(N-benzyloxycarbonyl(Cbz)amino)alkylphosphonate diesters was studied under positive ion electrospray ionization (ESI) conditions. Their fragmentation pathways are depicted and supported by tandem mass spectrometry. Besides the common eliminations of ether, benzyl alcohol, phosphite and an ether plus benzyl alcohol from molecular ions, the title compounds show a tendency to undergo an interesting intramolecular benzyl rearrangement to yield benzylphosphonate ions. The fragmentation patterns do not depend on the substituent attached to the alpha-carbon atom.

Enzyme Inhibitors↗
PubMed2003

Noncontact radio-frequency ablation for obtaining deeper lesions.

Radio-frequency (RF) cardiac catheter ablation has been very successful for treating some cardiac arrhythmias, however, the success rate for ventricular tachycardias is still not satisfactory. Some existing methods for developing deeper lesions include active cooling of the electrode and modifying the electrode shape. We propose a method of noncontact ablation, to solve this problem. We apply 120 W of power through an 8-mm electrode for a 120-s duration, with distances from 0 to 3 mm between electrode and myocardium, to create lesions in myocardium. We apply flow rates of 1, 3, and 5 L/min to determine their effect. Results show that with an optimal distance from 0.5 to 1.5 mm between electrode and myocardium, we increase lesion depth from 7.5 mm for contact ablation to 9.5 mm for noncontact ablation. For different flow rates, the optimal distance various. The effect of flow rate is not obvious. Higher flow rate does not lead to a deeper lesion.

Animals↗
PubMed2003

Study on the classification of chronic gastritis at molecular biological level.

AIM: To explore the pathophysiologibasis for the fact that patients with digestive tract symptoms do not necessarily have gastric mucosal pathology and those without clinical symptoms do not necessarily have no gastric mucosal pathology. METHODS: The ultrastructure, trace elements, cAMP, DNA, SOD and LPO in the gastric mucosa and its epithelial cells of 188 patients without organic lesions of heart, lung, liver, gallbladder, pancreas, kidney or intestine and basically histopathological normal persons (F) were detected synchronously by SEM, TEM, EDAX, Image analysis system RIA and (3)H-TdR Lymphocyte Transfer Test. RESULTS: The content of Zn, Cu, cAMP and (3)H-TdR LCT in gastric mucosa and the content of Zn, Cu, DNA and LPO in gastric mucosa epithelial nuclei of each group were shown as belows: Normal control (4.1+/-1.0, 5.2+/-0.8, 15.9+/-1.5, 1079.7+/-227.4, 7.6+/-0.4, 58.4+/-0.3, 12.6+/-2.7, 2.6+/-0.6); CSG without symptoms group (3.7+/-1.2, 5.1+/-1.8, 15.6+/-0.9, 924.5+/-234.9, 7.8+/-0.3, 58.6+/-0.4, 13.0+/-3.1, 2.9+/-0.4); CAG without symptoms group (3.3+/-1.0, 4.8+/-0.9, 14.9+/-0.7, 887.7+/-243.6, 7.8+/-0.3, 58.7+/-0.3, 14.3+/-2.8, 3.1+/-0.4); F type with symptoms group (3.5+/-1.4, 4.5+/-1.0, 15.7+/-1.4, 932.1+/-2449.3, 7.9+/-0.4, 58.7+/-0.5, 13.5+/-4.6, 2.9+/-0.7); CSG with symptoms group (2.8+/-1.9, 4.0+/-1.5, 14.2+/-1.8, 867.3+/-240.5, 8.1+/-0.5, 58.9+/-0.5, 15.2+/-3.2, 4.2+/-0.7); CAG with symptoms group (2.0+/-1.8, 3.4+/-1.5, 13.4+/-1.8, 800.9+/-221.8, 8.6+/-0.4, 59.3+/-0.5, 16.5+/-3.1, 4.5+/-0.6). The contents of Zn, Cu in mitochonondria and SOD in gastric mucosa of each group were shown as belows: Normal control group (9.2+/-0.5, 58.3+/-0.3, 170.5+/-6.1), CSG without symptoms group (8.9+/-0.5, 58.2+/-0.3, 167.2+/-5.3), CAG without symptoms group (8.8+/-0.4, 57.5+/-0.2, 166.1+/-4.2); F type with symptoms group (8.9+/-0.5, 58.0+/-0.3, 167.9+/-5.7), CSG with symptoms group (8.6+/-0.5, 57.8+/-0.3, 163.3+/-5.6); CAG with symptoms group (8.3+/-0.4, 57.5+/-0.3, 161.2+/-4.3). There were significant differences in these cases, P<0.05-0.001. There were synchronous changes of gastric mucosa epithelial cellular ultrastructure. The "background lesions" (focal atrophic gastritis, focal intestinal metaplasia, micro-ulcer) in nonfocal gastric mucosa of all groups had significant differences (P<0.05-0.001). CONCLUSION: Disease with symptoms, disease without symptoms, nondisease with symptoms occur on the basis of the quantitative changes of gastric mucosa epithelial cellular ultrastructure and related bioactive substances.

Cell Nucleolus↗
PubMed2003

Ultrastructure and molecular biological changes of chronic gastritis, gastric cancer and gastric precancerous lesions: a comparative study.

AIM: To carry out a comparative study on ultrastructure and molecular biological changes of chronic gastritis (CG), gastric cancer (GC) aand gastric precancerous lesions. METHODS: By the use of histochemical staining, SEM with EDAX, TEM with EDAX, image analysis technique, RIA and chemiluminescence method, gastric mucosa of 168 patients were synchronously analyzed in morphology, trace elements, DNA, cAMP, SOD, (3)H-TdR LCT and serum LPO were also done. RESULTS: The incidence of epithelial nucleoplasmic ratio >1, lobulated nuclei, inter-chromatin aggregation of granules, nucleolar hypertrophy, and the content of DNA, Zn, Cu in nuclei and serum LPO of each group were showed as belows: normal control group (0.0, 0.0, 6.7, 0.0, 12.6+/-2.7, 7.6+/-0.4, 58.4+/-0.3, 2.6+/-0.6), CSG group (5.7, 2.9, 7.4, 2.9, 15.2+/-3.1, 8.1+/-0.5, 58.9+/-0.5, 4.2+/-0.7), CAG group (31.3, 29.7, 45.3, 42.2, 16.5+/-3.1, 8.6+/-0.4, 59.3+/-0.5, 4.5+/-0.6), CA group (100.0, 100.0, 72.2, 50.0, 30.7+/-8.2, 8.8+/-0.3, 59.5+/-0.4, 6.8+/-1.6), ATP(++) group (61.5, 38.5, 23.1, 38.5, 23.5+/-8.9, 8.3+/-0.4, 59.1+/-0.4, 5.1+/-1.2), IM(++)+ATP(++)group (77.8, 55.5, 33.3, 44.4, 25.1+/-7.2, 8.4+/-0.5, 59.5+/-0.4, 6.5+/-1.1), IM(+++)+ATP(++) group (100.0, 100.0, 75.0, 62.5, 28.5+/-9.1, 8.9+/-0.5, 59.7+/-0.4, 7.6+/-0.7), IMII(b) group (100.0, 62.5, 75.0, 50.0, 27.3+/-10.3, 8.6+/-0.3, 59.5+/-0.4, 6.1+/-0.9); whereas the content of Zn, Cu in mitochondria and cAMP, SOD in gastric mucosa, and (3)H-TdR LCT of each group were showen as belows: normal control group (9.2+/-0.5, 58.3+/-0.3, 15.9+/-1.5, 170.5+/-6.1, 1079.7+/-227.4), CSG group (8.6+/-0.5, 57.8+/-0.3, 14.6+/-1.8, 163.3+/-5.6, 867.3+/-240.5), CAG group (8.3+/-0.4, 57.5+/-0.3, 13.4+/-1.8, 161.2+/-4.3, 800.9+/-221.8), CA group (8.9+/-0.4, 57.1+/-0.3, 10.2+/-3.9, 152.2+/-3.8, 325.7+/-186.8), ATP(++) group (9.1+/-0.4, 57.0+/-0.3, 12.4+/-1.8, 161.5+/-3.8, 642.9+/-174.3), IM(++)+ATP(++) group (8.6+/-0.4, 56.9+/-0.3, 12.0+/-2.3, 152.2+/-2.5, 326.3+/-160.3), IM(+++)+ATP(++) group (8.5+/-0.3, 56.8+/-0.2, 10.4+/-0.9, 147.4+/-2.6, 316.1+/-170.7), IMII(b) group (8.6+/-0.3, 56.9+/-0.3, 11.9+/-1.9, 150.0+/-2.8, 318.9+/-145.8), there were significant differences between groups (P<0.05-0.01). CONCLUSION: There was a significant difference between CG and GC in their ultrastructure and molecular biology. Only on the condition of changes of internal environment in combination with the harmful effect of external environment, chronic atrophic gastritis can then develop into gastric cancer. Hence it might have similar epithelial cell ultrastructure and molecular biological changes in ATP(++), IMII(b) and cancer, hence there were similar patterns of occurrence, development and transformation. Recognition of this trend might help to explore problems of prevention and cure.

Atrophy↗
PubMed2003

[Percutaneous hepatic puncture radio frequency ablation in the treatment of hepatocellular carcinoma].

OBJECTIVE: To observe the curative effect of percutaneous radio frequency ablation (PRFA) on hepatocellular carcinoma. METHODS: Under local or epidural anaesthesia, radio frequency electrodes were percutaneously introduced with ultrasound guide into the tumor in the liver for ablation. RESULTS: Among the 96 hepatic cancer lesions in 60 patients, 41 (42.7%) with diameter < 3.5 cm were ablated by one session. The effective rate (CR + PR) was 100% (41/41) with CR 92.6% (38/41) and PR 7.3% (3/41). During the 6 - 24 month follow up of these lesions, 36 (87.8%) of these 41 patients showed no recurrence by CT or MRI. Fifty-five (57.3%) lesions with diameter 3.5 cm < or = Phi < 12 cm were ablated by two or three sessions, with CR 3.6% (2/55), PR 67.3% (37/55) and CR + PR 70.9% (39/55) by CT or MRI in 1 to 3 months after the treatment. CONCLUSION: Percutaneous radio frequency ablation is effective on liver tumor with Phi < 3.5 cm. It is partly effective on lesions with 3.5 cm < or = Phi < 12 cm.

Adult↗