Evaluation of renal oxygenation change under the influence of carbogen breathing using a dynamic R2, R2′ and R2* quantification approach

The purpose of this study is to demonstrate the feasibility of dynamic renal R₂/R₂′/R₂* measurements based on a method, denoted psMASE‐ME, in which a periodic 180° pulse‐shifting multi‐echo asymmetric spin echo (psMASE) sequence, combined with a moving estimation (ME) strategy, is adopted. Following approval by the institutional animal care and use committee, a block design of respiratory challenge with interleaved air and carbogen (97% O₂, 3% CO₂) breathing was employed in nine rabbits. Parametrical R₂/R₂′/R₂* maps were computed and average R₂/R₂′/R₂* values were measured in regions of interest in the renal medulla and cortex. Bland–Altman plots showed good agreement between the proposed method and reference standards of multi‐echo spin echo and multi‐echo gradient echo sequences. Renal R₂, R₂′ and R₂* decreased significantly from 16.2 ± 4.4 s^?1, 9.8 ± 5.2 s^?1 and 25.9 ± 5.0 s^?1 to 14.9 ± 4.4 s^?1 (p < 0.05), 8.5 ± 4.1 s^?1 (p < 0.05) and 23.4 ± 4.8 s^?1 (p < 0.05) in the cortex when switching the gas mixture from room air to carbogen. In the renal medulla, R₂, R₂′ and R₂* also decreased significantly from 12.9 ± 4.7 s^?1, 15.1 ± 5.8 s^?1 and 27.9 ± 5.3 s^?1 to 11.8 ± 4.5 s^?1 (p < 0.05), 14.2 ± 4.2 s^?1 (p < 0.05) and 25.8 ± 5.1 s^?1 (p < 0.05). No statistically significant differences in relative R₂, R₂′ and R₂* changes were observed between the cortex and medulla (p = 0.72 for R₂, p = 0.39 for R₂′ and p = 0.61 for R₂*). The psMASE‐ME method for dynamic renal R₂/R₂′/R₂* measurements, together with the respiratory challenge, has potential use in the evaluation of renal oxygenation in many renal diseases     

Synthesis of Alternating Low‐Bandgap Conjugated Polymers Based on Dithieno[2,3‐d:2′,3′‐d′]naphtho[1,2‐b:3,4‐b′]dithiophene and Enhancement of Photovoltaic Properties with Solvent Additives

Two alternating low‐bandgap conjugated polymers with 10,11‐di(3,7‐dimethyloctyloxy)di‐thieno[2,3‐d:2′,3′‐d′]naphtho[1,2‐b:3,4‐b′]dithiophene (NDT) as electron‐donor moieties and N,N′‐di(2‐hexyldecyl)isoindigo (ID) or bis(thieno‐2‐yl)‐N,N′‐bis(2‐hexyldecyl)‐1,4‐dioxo‐pyrrolo[3,4‐c]pyrrole (DPP) as electron‐acceptor moieties, respectively named as PNDT‐ID and PNDT‐DPP, are firstly synthesized and characterized. The polymers exhibit appropriate energy levels, good solution processabilities and broad light absorption properties; the power conversion efficiencies (PCEs) of 0.16%–0.19% for the photovoltaic solar cells (PVCs) from the blend films of the polymers and [6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₁BM) are very low. The performances of the PVCs from the polymers are remarkably increased when a very small amount of 1,8‐diiodooctance (DIO) or diphenyl sulfide (DPS) is used as solvent additives, and the maximal PCEs of 3.79% and 5.01% are respectively achieved in the PVCs from the blend films of PNDT‐ID/PC₇₁BM (W:W, 1:1.5) and PNDT‐DPP/PC₇₁BM (W:W, 1:1.5), with DPS as solvent additives under 100 mW cm^?2 illumination (AM 1.5G).

     

Synthesis and Photovoltaic Characterization of Dithieno[3,2‐b:2′,3′‐d]thiophene‐Derived Narrow‐Bandgap Polymers

Three novel dithieno[3,2‐b:2′,3′‐d]thiophene‐based low‐bandgap polymers are synthesized by a Suzuki–Miyaura coupling reaction or by direct arylation polycondensation. The polymers present a high molecular weight (26–32 kDa) and narrow polydiversity (1.3–1.7). With a highest occupied molecular orbital (HOMO) energy level around ?5.20 eV, these polymers exhibit a narrow bandgap of 1.75–1.87 eV. All the polymers display strong absorption in the range of 350–700 nm. Bulk‐heterojunction (BHJ) solar cells are further fabricated by blending the as‐prepared polymer with (6,6)‐phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM) at different weight ratios. The best devices contribute a power conversion efficiency (PCE) of 0.73% under AM 1.5 (100 mW cm^?2).

     

Molecular mechanisms of 3,3′‐dichlorobenzidine‐mediated toxicity in HepG2 cells

3,3′‐Dichlorobenzidine (DCB) (CAS 91–94‐1), a synthetic, chlorinated, primary aromatic amine, is typically used as an intermediate in the manufacturing of pigments for printing inks, textiles, paints, and plastics. In this study, we found that DCB could significantly inhibit the cell viability of HepG2 cells in a concentration‐dependent manner. Flow cytometry revealed that DCB induced G2/M‐phase arrest and apoptosis in HepG2 cells. DCB treatment dramatically induced the dissipation of mitochondrial membrane potential (Δψ_m) and enhanced the enzymatic activities of caspase‐9 and caspase‐3 whilst hardly affecting caspase‐8 activity. Furthermore, Western blotting indicated that DCB‐induced apoptosis was accompanied by the down‐regulation of Bcl‐2/Bax ratio. These results suggested that DCB led to cytotoxicity involving activation of mitochondrial‐dependent apoptosis through Bax/Bcl‐2 pathways in HepG2 cells. Furthermore, HepG2 cells treated with DCB showed significant DNA damage as supported by the concentration‐dependent increase in olive tail moments as determined by the comet assay and by concentration‐ and time‐dependent increase in histone H2AX phosphorylation (γ‐H2AX). Two‐dimensional‐difference gel electrophoresis (2D‐DIGE), combined with mass spectrometry (MS), was used to unveil the differences in protein expression between cells exposed to 25 µM or 100 µM of DCB for 24 hr and the control cells. Twenty‐seven differentially expressed proteins involved in DNA repair, unfolded protein response, metabolism, cell signaling, and apoptosis were identified. Among these, 14‐3‐3 theta, CGI‐46, and heat‐shock 70 protein 4 were confirmed using Western blot assay. Taken together, these data suggest that DCB is capable of inducing DNA damage and some cellular stress responses in HepG2 cells, thus eventually leading to cell death by apoptosis. Environ. Mol. Mutagen. 55:407–420, 2014. © 2014 Wiley Periodicals, Inc.     

Magic angle effect on adiabatic T1ρ imaging of the Achilles tendon using 3D ultrashort echo time cones trajectory

The protons in collagen‐rich musculoskeletal (MSK) tissues such as the Achilles tendon are subject to strong dipolar interactions which are modulated by the term (3cos²θ‐1) where θ is the angle between the fiber orientation and the static magnetic field B₀. The purpose of this study was to investigate the magic angle effect in three‐dimensional ultrashort echo time Cones Adiabatic T_1ρ (3D UTE Cones‐AdiabT_1ρ) imaging of the Achilles tendon using a clinical 3 T scanner. The magic angle effect was investigated by Cones‐AdiabT_1ρ imaging of five cadaveric human Achilles tendon samples at five angular orientations ranging from 0° to 90° relative to the B₀ field. Conventional Cones continuous wave T_1ρ (Cones‐CW‐T_1ρ) and Cones T₂* (Cones‐T₂*) sequences were also applied for comparison. On average, Cones‐AdiabT_1ρ increased 3.6‐fold from 13.6 ± 1.5 ms at 0° to 48.4 ± 5.4 ms at 55°, Cones‐CW‐T_1ρ increased 6.1‐fold from 7.0 ± 1.1 ms at 0° to 42.6 ± 5.2 ms at 55°, and Cones‐T2* increased 12.3‐fold from 2.9 ± 0.5 ms at 0° to 35.8 ± 6.4 ms at 55°. Although Cones‐AdiabT_1ρ is still subject to significant angular dependence, it shows a much‐reduced magic angle effect compared to Cones‐CW‐T_1ρ and Cones‐T₂*, and may be used as a novel and potentially more effective approach for quantitative evaluation of the Achilles tendon and other MSK tissues.     

Different effects of furosemide on urinary excretion of prostaglandin E2 and F2α in rabbits

The effect of a constant infusion of furosemide (130 μg/min i.v. for 60 min, n = 8) was studied on urinary excretion of water, electrolytes and immunoreactive prostaglandin E₂ (iPGE₂) and iPGF_2α in chloralose-urethane anesthetized rabbits. During the furosemide infusion sodium and water excretion increased tenfold and the excretion of potassium and iPGE₂ two to three times. The excretion of iPGF_2α (0.06 ± 0.03 μg/min/100 g kidney weight) was not significantly changed during the furosemide infusion but increased markedly after the infusion and reached a maximum (1.0 ± 0.6 μg/min/100 g) 30 to 45 min later, while the small increase in iPGE₂ excretion at this time could be attributed to cross-reaction with PGF_2α The results indicate that PGE₂ might possibly be involved directly in the action of furosemide, while PGF_2α might participate in sodium and water conserving mechanisms in the rabbit kidney, activated by the drug induced diuresis.     

A pilot validation of multi‐echo based echo‐planar correlated spectroscopic imaging in human calf muscles

A current limitation of MR spectroscopic imaging of multiple skeletal muscles is prolonged scan duration. A significant reduction in the total scan duration using the echo‐planar correlated spectroscopic imaging (EP‐COSI) sequence was accomplished using two bipolar readout trains with different phase‐encoded echoes for one of two spatial dimensions within a single repetition time (TR). The second bipolar readout was used for spatially encoding the outer k‐space, whereas the first readout was used for the central k‐space only. The performance of this novel sequence, called multi‐echo based echo‐planar correlated spectroscopic imaging (ME‐EPCOSI), was demonstrated by localizing specific key features in calf muscles and bone marrow of 11 healthy volunteers and five subjects with type 2 diabetes (T2D). A 3 T MRI–MRS scanner equipped with a transmit–receive extremity coil was used. Localization of the ME‐EPCOSI sequence was in good agreement with the earlier single‐readout based EP‐COSI sequence and the required scan time was reduced by a factor of two. In agreement with an earlier report using single‐voxel based 2D MRS, significantly increased unsaturated pools of intramyocellular lipid (IMCL) and extramyocellular lipid (EMCL) and decreased IMCL and EMCL unsaturation indices (UIs) were observed in the soleus and tibialis anterior muscle regions of subjects with T2D compared with healthy controls. In addition, significantly decreased choline content was observed in the soleus of T2D subjects compared with healthy controls. Multi‐voxel characterization of IMCL and EMCL ratios and UI in the calf muscle may be useful for the non‐invasive assessment of altered lipid metabolism in the pathophysiology of T2D. Copyright © 2014 John Wiley & Sons, Ltd.     

Middle cerebral artery blood velocity during exercise with β‐1 adrenergic and unilateral stellate ganglion blockade in humans

A reduced ability to increase cardiac output (CO) during exercise limits blood flow by vasoconstriction even in active skeletal muscle. Such a flow limitation may also take place in the brain as an increase in the transcranial Doppler determined middle cerebral artery blood velocity (MCA V_mean) is attenuated during cycling with β‐1 adrenergic blockade and in patients with heart insufficiency. We studied whether sympathetic blockade at the level of the neck (0.1% lidocain; 8 mL; n=8) affects the attenuated exercise – MCA V_mean following cardio‐selective β‐1 adrenergic blockade (0.15 mg kg^?1 metoprolol i.v.) during cycling. Cardiac output determined by indocyanine green dye dilution, heart rate (HR), mean arterial pressure (MAP) and MCA V_mean were obtained during moderate intensity cycling before and after pharmacological intervention. During control cycling the right and left MCA V_mean increased to the same extent (11.4 ± 1.9 vs. 11.1 ± 1.9 cm s^?1). With the pharmacological intervention the exercise CO (10 ± 1 vs. 12 ± 1 L min^?1; n=5), HR (115 ± 4 vs. 134 ± 4 beats min^?1) and ΔMCA V_mean (8.7 ± 2.2 vs. 11.4 ± 1.9 cm s^?1) were reduced, and MAP was increased (100 ± 5 vs. 86 ± 2 mmHg; P < 0.05). However, sympathetic blockade at the level of the neck eliminated the β‐1 blockade induced attenuation in ΔMCA V_mean (10.2 ± 2.5 cm s^?1). These results indicate that a reduced ability to increase CO during exercise limits blood flow to a vital organ like the brain and that this flow limitation is likely to be by way of the sympathetic nervous system.     

A frequent TG deletion near the polyadenylation signal of the human HEXB gene: Occurrence of an irregular DNA structure and conserved nucleotide sequence motif in the 3′ untranslated region

While screening for new mutations in the HEXB gene, which encodes the β-subunit of β-hexosaminidase, a TG deletion (ΔTG) was found in the 3′ untranslated region (3′UTR) of the gene, 7 bp upstream from the polyadenylation signal. Examination of DNA samples of 145 unrelated Argentinean individuals from different racial backgrounds showed that the ΔTG allele was present with a frequency of approximately 0.1, compared with the wild-type (WT) allele. The deletion was not associated with infantile or variant forms of Sandhoff disease when present in combination with a deleterious allele. Total Hex and Hex B enzymatic activities measured in individuals heterozygous for ΔTG and a null allele, IVS-2+1G→A (G→A), were approximately 30% lower than the activities of G→A/WT individuals. Analysis of the HEXB mRNA from leukocytes of ΔTG/WT individuals by RT-PCR of the 3′UTR showed that the ΔTG allele is present at lower level than the WT allele. By polyacrylamide gel electrophoresis, it was determined that a PCR fragment containing the +TG version of the 3′UTR of the HEXB gene had an irregular structure. On inspection of genes containing a TG dinucleotide upstream from the polyadenylation signal we found that this dinucleotide was part of a conserved sequence (TGTTTT) immersed in a A/T-rich region. This sequence arrangement was present in more than 40% analyzed eukaryotic mRNAs, including in the human, mouse and cat HEXB genes. The significance of the TG deletion in reference to Sandhoff disease as well as the possible functional role of the consensus sequence and the DNA structure of the 3′UTR are considered. Hum Mutat 12:320–329, 1998.© 1998 Wiley-Liss, Inc.     

Defects in tRNA Anticodon Loop 2′‐O‐Methylation Are Implicated in Nonsyndromic X‐Linked Intellectual Disability due to Mutations in FTSJ1

tRNA modifications are crucial for efficient and accurate protein synthesis, and modification defects are frequently associated with disease. Yeast trm7Δ mutants grow poorly due to lack of 2′‐O‐methylated C₃₂ (Cm₃₂) and Gm₃₄ on tRNA^Phe, catalyzed by Trm7‐Trm732 and Trm7‐Trm734, respectively, which in turn results in loss of wybutosine at G₃₇. Mutations in human FTSJ1, the likely TRM7 homolog, cause nonsyndromic X‐linked intellectual disability (NSXLID), but the role of FTSJ1 in tRNA modification is unknown. Here, we report that tRNA^Phe from two genetically independent cell lines of NSXLID patients with loss‐of‐function FTSJ1 mutations nearly completely lacks Cm₃₂ and Gm₃₄, and has reduced peroxywybutosine (o2yW₃₇). Additionally, tRNA^Phe from an NSXLID patient with a novel FTSJ1‐p.A26P missense allele specifically lacks Gm₃₄, but has normal levels of Cm₃₂ and o2yW₃₇. tRNA^Phe from the corresponding Saccharomyces cerevisiae trm7‐A26P mutant also specifically lacks Gm₃₄, and the reduced Gm₃₄ is not due to weaker Trm734 binding. These results directly link defective 2’‐O‐methylation of the tRNA anticodon loop to FTSJ1 mutations, suggest that the modification defects cause NSXLID, and may implicate Gm₃₄ of tRNA^Phe as the critical modification. These results also underscore the widespread conservation of the circuitry for Trm7‐dependent anticodon loop modification of eukaryotic tRNA^Phe.     

Frequent occurrence of in vivo clonal expansion of CD4− CD8− T cells bearing T cell receptor αβ chains in adult humans

We have previously reported 2 cases of healthy men showing in vivo monoclonal expansion of mature CD4^? CD8^? αβ T cells. In the present study, an additional 3 adults were found to exhibit such an expansion, among a total 464 adult donors studied. These 5 individuals were otherwise physiologically normal, with no history of severe illness and autoimmune disease at the time of examination. To investigate the mechanisms of the clonal expansion, further characterization of the clonal cells was attempted. No apparent preference for usage of the Tcell receptor β chain variable region was observed in the clonal T cells. These clonal T cells showed lectin-dependent or redirected antibody-dependent cell-mediated cytotoxicities, whereas they could not lyse autologous lymphoblastoid cell lines. Failure of Fas antigen expression was not observed for any of these clones. These results suggest that clonal expansion of CD4^? CD8^? αβ T cells frequently occurs in the periphery without any T cell abnormalities.     

Quantitative three‐dimensional ultrashort echo time cones imaging of the knee joint with motion correction

Knee degeneration involves all the major tissues in the joint. However, conventional MRI sequences can only detect signals from long T2 tissues such as the superficial cartilage, with little signal from the deep cartilage, menisci, ligaments, tendons and bone. It is highly desirable to develop new sequences that can detect signal from all major tissues in the knee. We aimed to develop a comprehensive quantitative three‐dimensional ultrashort echo time (3D UTE) cones imaging protocol for a truly “whole joint” evaluation of knee degeneration. The protocol included 3D UTE cones actual flip angle imaging (3D UTE‐Cones‐AFI) for T₁ mapping, multiecho UTE‐Cones with fat suppression for T₂* mapping, UTE‐Cones with adiabatic T_1ρ (AdiabT_1ρ) preparation for AdiabT_1ρ mapping, and UTE‐Cones magnetization transfer (UTE‐Cones‐MT) for MT ratio (MTR) and modeling of macromolecular proton fraction (f). An elastix registration technique was used to compensate for motion during scans. Quantitative data analyses were performed on the registered data. Three knee specimens and 15 volunteers were evaluated at 3 T. The elastix motion correction algorithm worked well in correcting motion artifacts associated with relatively long scan times. Much improved curve fitting was achieved for all UTE‐Cones biomarkers with greatly reduced root mean square errors. The averaged T₁, T₂*, AdiabT_1ρ, MTR and f for knee joint tissues of 15 healthy volunteers were reported. The 3D UTE‐Cones quantitative imaging techniques (ie, T₁, T₂*, AdiabT_1ρ, MTR and MT modeling) together with elastix motion correction provide robust volumetric measurement of relaxation times, MTR and f of both short and long T₂ tissues in the knee joint.     

Relation between Plasma Homocysteine Concentration, the 844ins68 Variant of the Cystathionine β-Synthase Gene, and Pyridoxal-5′-Phosphate Concentration

A moderately elevated plasma total homocysteine (tHcy), whether measured during fasting or post-methionine load (PML), is recognized as a risk factor for coronary artery diseases (CAD). Cystathionine β-synthase (CBS), a key enzyme in the transsulfuration pathway, is important for the metabolism of homocysteine. In recent years, a relatively prevalent mutation, the 844ins68 (68-bp insertion), was found to be carried by about 12% of the general population. In the current investigation, we studied 741 individuals with respect to the effect of the 68-bp insertion of the CBS gene on fasting and PML tHcy, and also determined the level of pyridoxal-5′-phosphate (vitamin B₆), a cofactor of the CBS enzyme. Our results showed that the mean fasting and PML increase in tHcy levels were lower in individuals carrying the 844ins68 variant compared to those without the insertion; although only the difference in PML increase in tHcy reached statistical significance (P = 0.02). When these individuals were divided into two groups based on vitamin B₆ concentration, the PML increase in tHcy was significantly lower in individuals heterozygous for the insertion compared to those without the insertion only in the group of individuals whose vitamin B₆ concentrations were below the sample median (38.0 nmol/L). We speculate that the 68-bp insertion is associated with somewhat higher levels of CBS enzyme activity, and that the effect of this becomes more pronounced in the presence of relatively low concentrations of pyridoxal-5′-phosphate, a cofactor of the CBS enzyme.     

A mutation creating an upstream translation initiation codon in SLC22A5 5′UTR is a frequent cause of primary carnitine deficiency

Primary carnitine deficiency is caused by a defect in the active cellular uptake of carnitine by Na⁺‐dependent organic cation transporter novel 2 (OCTN2). Genetic diagnostic yield for this metabolic disorder has been relatively low, suggesting that disease‐causing variants are missed. We Sanger sequenced the 5′ untranslated region (UTR) of SLC22A5 in individuals with possible primary carnitine deficiency in whom no or only one mutant allele had been found. We identified a novel 5′‐UTR c.‐149G>A variant which we characterized by expression studies with reporter constructs in HeLa cells and by carnitine‐transport measurements in fibroblasts using a newly developed sensitive assay based on tandem mass spectrometry. This variant, which we identified in 57 of 236 individuals of our cohort, introduces a functional upstream out‐of‐frame translation initiation codon. We show that the codon suppresses translation from the wild‐type ATG of SLC22A5, resulting in reduced OCTN2 protein levels and concomitantly lower transport activity. With an allele frequency of 24.2% the c.‐149G>A variant is the most frequent cause of primary carnitine deficiency in our cohort and may explain other reported cases with an incomplete genetic diagnosis. Individuals carrying this variant should be clinically re‐evaluated and monitored to determine if this variant has clinical consequences.     

Asymmetric dimethylarginine (ADMA) induces chronic kidney disease through a mechanism involving collagen and TGF‐β1 synthesis

Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase (NOS) inhibitor, is accumulated in plasma during chronic kidney disease (CKD). It is considered an independent mortality and cardiovascular risk factor in CKD patients. To test the involvement of ADMA in CKD progression, we investigated the effects of chronic ADMA administration on renal structure and compared these effects with $N^{\rm{G}}$ ‐nitro‐L ‐arginine methyl ester (L‐NAME) treatment, a widely used exogenous inhibitor of NOS that induces CKD. Three groups of uninephrectomized mice were studied: ADMA (60 mg/kg per day), L‐NAME (60 mg/kg per day), and isotonic saline (control) were infused through osmotic mini‐pumps for 8 weeks. ADMA and L‐NAME induced hypertension (PAS 167 ± 16 and 168 ± 10 versus 100 ± 4 mmHg, p < 0.01, respectively). High level of ADMA was associated with increased renal oxidative stress. ADMA treatment induced glomerular and vascular fibrosis as evidenced by the elevated deposits of collagen I, III, and fibronectin (p < 0.01). A similar profile was observed in the L‐NAME group. Mice treated with ADMA had reduced peritubular capillaries versus controls (p < 0.01). Collagen I mRNA expression and renal TGF‐β1 concentrations were higher in the ADMA and L‐NAME groups. Increased level of TGF‐β1 was associated with a significant rise of HIF‐1α and endothelin‐1 expression. These results demonstrate for the first time that elevated concentrations of ADMA are associated with the development of renal fibrosis. These data suggest that in pathophysiological conditions of endothelial dysfunction, the exaggerated endogenous synthesis of ADMA could contribute to CKD progression by favouring hypertension, extracellular matrix synthesis, and rarefaction of peritubular capillaries. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Expression of HNF-1α and HNF-1β in various histological differentiations of hepatocellular carcinoma

Hepatic nuclear factor 1 (HNF-1) regulates genes in a hepatocyte-specific manner. It has been previously reported that the ratio of HNF-1α and HNF-1β mRNA is related to histological differentiation hepatocellular carcinoma (HCC). In this study, the expression levels of the HNF-1α and HNF-1β proteins were analysed relatively and quantitatively in various histologically differentiated HCC and surrounding non-cancerous tissues, and HNF-1α binding activity for the AT element of the B domain of the human α-fetoprotein enhancer was examined. Western blot analysis demonstrated that HNF-1α protein was expressed at a higher level in well-differentiated HCC tissues than in the surrounding non-HCC tissues; on the other hand, the HNF-1α protein was expressed at lower levels in moderately and poorly differentiated HCCs than in the surrounding non-HCC tissues. The levels of HNF-1β expression in well-differentiated and poorly differentiated HCCs were similar to and higher than those found in the respective surrounding non-cancerous portions. In binding assays, HNF-1 binding activity was high in well-differentiated HCC and lower in moderately and poorly differentiated HCCs. Most well-differentiated HCC cases showed immunohistochemical expression of HNF-1α. These findings show that poor histological differentiation of HCC correlates with decreases in the level and activity of HNF-1α proteins. © 1998 John Wiley & Sons, Ltd.