Causal Effect of Chondroitin, Glucosamine, Vitamin, and Mineral Intake on Kidney Function: A Mendelian Randomization Study

The causal effects of chondroitin, glucosamine, and vitamin/mineral supplement intake on kidney function remain unknown, despite being commonly used. We conducted a two-sample summary-level Mendelian randomization (MR) analysis to test for causal associations between regular dietary supplement intake and kidney function. Genetic instruments for chondroitin, glucosamine, and vitamin/mineral supplement intake were obtained from a genome-wide association study of European ancestry. Summary statistics for the log-transformed estimated glomerular filtration rate (log-eGFR) were provided by the CKDGen consortium. The multiplicative random-effects inverse-variance weighted method showed that genetically predicted chondroitin and glucosamine intake was causally associated with a lower eGFR (chondroitin, eGFR change beta = -0.113%, standard error (SE) = 0.03%, p-value = 2 × 10-4; glucosamine, eGFR change beta = -0.240%, SE = 0.035%, p-value = 6 × 10-12). However, a genetically predicted vitamin/mineral supplement intake was associated with a higher eGFR (eGFR change beta = 1.426%, SE = 0.136%, p-value = 1 × 10-25). Validation analyses and pleiotropy-robust MR results for chondroitin and vitamin/mineral supplement intake supported the main results. Our MR study suggests a potential causal effect of chondroitin and glucosamine intake on kidney function. Therefore, clinicians should carefully monitor their long-term effects.

Retroductal Delivery of Epidermal Growth Factor Protects Salivary Progenitors after Irradiation

Salivary gland hypofunction after irradiation is associated with a deficit of epithelial stem/progenitors in salivary glands. Although epidermal growth factor (EGF) is known to stimulate the proliferation of epithelial cells, the therapeutic effect of EGF on salivary epithelial stem/progenitors remains undetermined. In this study, we administered EGF to submandibular glands (SMGs) via a retrograde route through the SMG excretory duct before fractionated irradiation and examined whether EGF could protect salivary epithelial progenitor cells from radiation and alleviate radiation-induced salivary hypofunction. EGF-treated mice exhibited greater body and gland weights at 12 wk after irradiation than untreated mice. The retroductal delivery of EGF improved salivary secretory function and increased salivary amylase activity in a dose-dependent manner. Histological examinations highlighted the amelioration of the loss of keratine-14⁺ (KRT14⁺) basal ductal and/or MIST1⁺ acinar cells, as well as induction of fibrosis, following irradiation in EGF-treated mice. An additional in vitro experiment using a salivary gland organoid irradiation model indicated that the radioprotective effects of EGF promoted the growth and inhibited the apoptotic cell death of salivary epithelial cells. Our results suggest that retroductal delivery of EGF may be a promising therapeutic option for preventing radiation-induced salivary gland hypofunction.

Solitary Fibrous Tumor in Buccal Cheek Mucosa

A solitary fibrous tumor is a relatively uncommon neoplasm that usually occurs in the pleura but occurs extremely rarely in the oral cavity. Reported herein is a rare case of a solitary fibrous tumor in the buccal cheek mucosa. A 50-year-old man visited the authors' hospital due to a buccal cheek mass whose size had increased. Excisional biopsy was done under local anesthesia. After the excisional biopsy, the patient was diagnosed to have a solitary fibrous tumor. In immunohistochemistry, the patient's solitary fibrous tumor was characterized by the expression of CD34 and CD99 on the neoplastic cells, and negativity for Bcl-2 and S-100. No recurrence or complication occurred for a period of 5 years. The growth of a primary solitary fibrous tumor in the buccal cheek mucosa is extremely rare and has been rarely reported in the South Korean medical literature. A solitary fibrous tumor must be distinguished from other spindle cell tumors. Presented herein is a case of primary solitary fibrous tumor in the buccal cheek mucosa. The relevant literature is briefly reviewed.

The Efficacy of Coblator in Turbinoplasty

Background

Turbinate hypertrophy is one of the common causes of chronic nasal obstruction. In principle, therapeutic guidelines recommend medical treatment. Failure to treat turbinate thickening despite drug therapy may indicate the need for surgery. The main aim of this study was to determine the effect of radiofrequency surgery, among various other surgical procedures, on people with both nasal septal deviation and turbinate hypertrophy.

Methods

Among people with nasal deviation who visited the subject hospital between July 2008 to July 2014, 21 people with nasal septal deviation and severe turbinate hypertrophy before their surgery had undergone septoplasty with turbinoplasty using radiofrequency combined with septoplasty. The degree of the turbinate's hypertrophy was appraised in all the patients before and after the surgery using the rhinoscopy, and acoustic rhinometry was objectively carried out. The subjective effect of the turbinoplasty using radiofrequency was explored through the visual analog scale (VAS) score.

Results

The degree of contraction of the nasal mucosa after the rhinoscopy changed from Grades 3 and 4 (100%) to Grades 1 and 2 (95.2%) and Grades 3 (4.8%). The minimal cross-sectional area significantly increased from 0.44±0.07 to 0.70±0.07 cm² (p<0.05). The nasal cavity volume increased from 4.79±0.49 to 6.76±0.55 cm² (p<0.05). The subjective symptoms evaluated with VAS score a year after the surgery significantly improved (p<0.05).

Conclusion

Turbinoplasty using Coblator with septoplasty is an effective treatment method because it expands nasal cavity, has a low incidence of complications, subjectively improves symptoms, and has short treatment duration.

Comparison of alfuzosin 10 mg with or without propiverine 10 mg, 20 mg in men with lower urinary tract symptom and an overactive bladder: randomised, single-blind, prospective study

PURPOSE

The efficacy and safety of treatment with alfuzosin 10 mg plus propiverine 10 or 20 mg in men with lower urinary tract symptoms (LUTS) and an overactive bladder were investigated.

MATERIALS AND METHODS

In this parallel-arm, prospective, multicentre, single-blind study, men who were ≥ 40 years old, had an International Prostate Symptom Score (IPSS) of ≥ 8, an Overactive Bladder Symptom Score (OABSS) of ≥ 3 and an OABSS urgency item score of ≥ 2 were randomised in a 1 : 1 :1 ratio to receive alfuzosin 10 mg alone (Group A) or with propiverine 10 mg (Group B) or 20 mg (Group C) for 8 weeks. Four and 8 weeks after commencing treatment, OABSS was measured along with IPSS, maximal urinary flow rate (Qmax ) and postvoid residual volume (PVR). Adverse events were recorded.

RESULTS

A total of 135 men, including 43 in Group A, 48 in Group B and 44 in Group C, completed the study. Relative to baseline, all groups demonstrated significant reductions in OABSS and the IPSS after eight treatment weeks (p < 0.005). The improvement of OABSS in Group C was significantly greater than Group A and B (Group A: 0.70 ± 1.94; Group B: 2.50 ± 2.98; Group C: 4.30 ± 3.40; p < 0.005). An observed improvement of Qmax and PVR in the three groups did not achieve statistical significance. Overall adverse event rates were higher in Group C but not significant compared with others.

CONCLUSION

In patients with LUTS and overactive bladder, combined therapy with alfuzosin 10 mg plus propiverine 20 mg was significantly more effective than alfuzosin monotherapy and propiverine 10 mg combined therapy in terms of improving OABSS while not significantly affecting Qmax or PVR.

Preliminary study for gait phases detection to develop a rehabilitation equipment for hemiplegic patients

Preliminary experiment for analyzing weight shift during gait phases for hemiplegic patients was carried out to develop rehabilitation equipment. A gait phase detection system using pressure sensors was developed and the experiment was carried out for eight hemiplegic patients and normal adult. The weight shift during gait phases for a normal adult showed symmetrical for left and right footing phase, but that for the hemiplegic patients showed asymmetrical footing phase. However, it gave sufficient information to discriminate between left and right footing phases.

Comparison of efficacy for erectile function and lower urinary tract symptoms of tadalafil 20 mg on-demand and 5 mg once daily in patients with erectile dysfunction

Aim:  To compare the improvement in erectile dysfunction (ED) and lower urinary tract symptoms (LUTS) as well as safety of tadalafil dosed at 20 mg on-demand and 5 mg once daily among ED patients. Materials and methods:  A total of 194 ED patients visited between March 2010 and June 2011 were recruited. Out of 194 individuals, 168 (86.6%) met inclusion criteria after completing the two-week screening period (V0). The Patients were randomly allocated into two groups: (i) 20 mg of tadalafil as needed (Group 1: n = 84, 50.0%) and (ii) 5 mg of tadalafil once daily (Group 2: n = 84, 50.0%). Blood pressure (BP), heart rate (HR) and the five-item version of the International Index of Erectile Function (IIEF-5) were assessed immediately before initiation of treatment (V1) and after four (V2) and twelve weeks of treatment (V3). In men with an IPSS of ≥ 8 at V1, IPSS, maximal flow rate (Qmax) and post-void residual volume (PVR) were also assessed. Results:  Of the 168 patients, 134 (79.8%; Group 1: n = 68, 81.0%; Group 2: n = 66, 78.6%) patients completed the trial. IIEF-5 improved in both groups, and the mean change was larger in Group 2 at V3 (4.9 ± 4.2 vs. 6.5 ± 4.5; p = 0.032) Similarly, though IPSS (with ≥ 8, n = 88, 65.7%; Group 1: n = 44, 64.7%; Group 2: n = 44, 66.7%) improved in both groups, the mean change was larger in Group 2 at V3 (-2.8 ± 4.3 vs. -4.8 ± 4.1; p = 0.026). Qmax and PVR did not differ significantly in either group. Conclusions:  Once daily tadalafil was more efficacious in treating both ED and LUTS than on-demand dosing. However, no differences were observed between the two dosing schedules with regard to the improvement in LUTS when stratified by improvement in ED. The side effects were insignificant for both dosing schedules.

Contrast-enhanced MR cholangiography: comparison of Gd-EOB-DTPA and Mn-DPDP in healthy volunteers

OBJECTIVE

The purpose of this study was to compare the biliary enhancement dynamics of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) and mangafodipir trisodium (Mn-DPDP) for contrast-enhanced MR cholangiography (MRC) in healthy subjects.

METHODS

15 healthy volunteers underwent MRI at 1.5 T with volumetric interpolated breath-hold examination sequence. Each volunteer was scanned once for each contrast agent. The signal-to-noise ratio (SNR) of the liver parenchyma and common hepatic duct (CHD) and the contrast-to-noise ratio (CNR) of CHD to liver parenchyma were evaluated and compared before and at several time points (5, 15, 30, 45, 60, 90, and 120 min) after injection of each agent.

RESULTS

SNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP in liver parenchyma after 5 min and in CHD after 15 min (p<0.05). CNR of CHD to liver parenchyma using Gd-EOB-DTPA showed an initial decrease at 5 min post-injection followed by a steep increase to a peak at 15 min post-injection. CNR using Mn-DPDP showed a steady increase to a peak at 15 min post-injection without an initial decrease. At 15 min, the value of CNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP (p<0.05).

CONCLUSION

For both contrast agents, CNR reached a peak at 15 min after contrast injection. At this time point, CNR of Gd-EOB-DTPA was significantly higher than that of Mn-DPDP. Therefore, Gd-EOB-DTPA may provide better contrast-enhanced MRC than Mn-DPDP at 15 min after contrast administration.

De novo autoimmune hepatitis in Korean children after liver transplantation: a single institution's experience

INTRODUCTION

De novo autoimmune hepatitis (AIH) after orthotopic liver transplantation (OLT) has been described as a new type of late graft dysfunction in children who have not undergone transplantation for previous autoimmune liver disease. The purpose of this study was to evaluate the clinical aspects of de novo AIH among children following OLT.

PATIENTS AND METHODS

Between January 1994 and May 2007, 149 children underwent OLT, including 1 with recurrent AIH who was excluded from this study, whereas 4 others developed de novo AIH (2.7%; n = 4/148). We analyzed the demographics, laboratory characteristics, and response to treatment of the 4 children with de novo AIH following OLT.

RESULTS

The 4 patients were all girls with a median interval after OLT to presentation of 6.5 years (range, 0.7-8.8 years). The median age when de novo AIH developed was 12.4 years (range, 8.7-17.3 years). All cases were detected by abnormal liver function tests, namely, increased aspartate aminotransferase (AST; median, 322 IU/L; range, 181-919 IU/L). One patient showed elevated immunoglobulin G. Three patients displayed positive antinuclear antibodies. All were seronegative for smooth muscle antibody and liver-kidney microsomal type 1 antibody. One patient showed anti-mitochondrial antibody. All patients were treated with steroids with or without azathioprine. The liver function tests in these 4 patients, improved by at least 50% during the first month of treatment, responding to steroid treatment with or without azathioprine.

CONCLUSION

In preadolescent or adolescent female patients with unexplained graft dysfunction after OLT, it is important to recognize de novo AIH rapidly and to develop an adequate diagnostic strategy, including evaluation of serum autoantibodies, immunoglobulin G, and liver biopsy.

Renal protection by 3H-1,2-dithiole-3-thione against cisplatin through the Nrf2-antioxidant pathway

Cisplatin is commonly used for the treatment of several solid tumors. However, its clinical use is often limited by renal toxicity. The indirect antioxidant 3H-1,2-dithiole-3-thione (D3T) has been known to protect cells from oxidative damage by up-regulating the expression of antioxidative genes through the transcription factor NF-E2-related factor 2 (Nrf2) pathway. We hypothesized that D3T treatment may be protective against cisplatin-induced nephrotoxicity by enhancing the antioxidative capacity of renal cells. In cultured murine tubular epithelial cells, D3T facilitates the nuclear accumulation of Nrf2 and the subsequent expression of its target genes such as glutamate cysteine ligase (GCL). Increased GSH pool in D3T-treated renal cells appears to be associated with amelioration of cisplatin-mediated cell death. Protective effects of D3T were also observed in mice. Oral administration of D3T (0.25mmol/kg) increased the expression of GCL in mouse kidney, which resulted in suppression of cisplatin-mediated increases in blood urea nitrogen and serum creatinine. Histopathological changes representing cisplatin-induced acute renal failure were also effectively ameliorated by D3T treatment. Collectively, these results indicate that pharmacological activation of the Nrf2 pathway might have a beneficial effect on reducing chemotherapy-associated cytotoxic adverse effects.

Role of the Nrf2-antioxidant system in cytotoxicity mediated by anticancer cisplatin: implication to cancer cell resistance

The treatment of alkylating cytotoxic drug cisplatin is often limited by high incidence rate of resistance. In the present study, the potential involvement of the transcription factor Nrf2 in determination of cisplatin cytotoxicity has been investigated. Nrf2-deficient murine embryonic fibroblasts showed increased cell death, cytotoxicity, and apoptosis in response to cisplatin treatment compared to wild-type cells. Cisplatin-resistant human ovarian cancer SK-OV cells, which are retaining 25-fold higher levels of GSH than murine fibroblasts, could be sensitized by inhibition of Nrf2. Transfection with Nrf2 siRNA into SK-OV cells resulted in severe degree of GSH depletion and exacerbated cytotoxicity following cisplatin treatment compared to scrambled RNA control. In conclusion, we propose that the Nrf2 pathway, which plays a protective role in normal cells, can be a potential target to control cancer cell resistance to oxidants, cytotoxic chemicals, and radiation.

Role of increased expression of the proteasome in the protective effects of sulforaphane against hydrogen peroxide-mediated cytotoxicity in murine neuroblastoma cells

The 26S proteasome is responsible for degradation of abnormal proteins and may play a role in cell survival upon oxidative stress. The indirect antioxidant sulforaphane (SFN) protects animal tissues from chemical toxicants by increasing the expression of several families of Nrf2-regulated genes. The role of induction of the 26S proteasome in cytoprotection by SFN was investigated in murine neuroblastoma Neuro2A cells. SFN enhanced the expression of the catalytic subunits of the proteasome, as well as proteasomal peptidase activities in these cells. Such treatment with SFN protected cells from hydrogen peroxide-mediated cytotoxicity in a manner dependent on proteasomal function. Inhibition of proteasome activities using pharmacological interventions significantly attenuated the protective effects of SFN against hydrogen peroxide cytotoxicity, as well as protein oxidation. Moreover, overexpression of the catalytic subunit PSMB5 enhanced proteasome function and led to elevated resistance against hydrogen peroxide toxicity and extent of protein oxidation compared to blank-plasmid-transfected cells. Pretreatment of PSMB5-overexpressing cells with SFN did not further enhance this resistance. Collectively, these results suggest that the cytoprotective effects of SFN against oxidative stress are in part due to up-regulation of the proteasome system. Therefore, inducers of proteasome expression may ameliorate the accumulation of damaged proteins associated with neurodegeneration and other diseases in whose etiologies protein oxidation plays a role.

Induction of Nrf2-regulated genes by 3H-1, 2-dithiole-3-thione through the ERK signaling pathway in murine keratinocytes

Electrophile and free radical detoxifying enzymes including NAD(P)H:quinine oxidoreductase 1 (Nqo1) play an important role in the defense system by enhancing cellular antioxidant capacity. Chemopreventive efficacy of 3H-1,2-dithiole-3-thione (D3T) is mediated through activation of the transcription factor Nrf2 and subsequent elevation of detoxifying enzymes. In the present study, we have investigated the potential role of extracellular signal-regulated kinase (ERK) in regulation of D3T-induced and Nrf2-dependent gene expression in murine keratinocytes. Expression levels of Nqo1 were highly inducible by D3T treatment and increased nuclear levels of Nrf2 were observed in these cells. Treatment with pharmacological inhibitor of ERK1/2 largely blocked nuclear accumulation of Nrf2, ARE-driven reporter gene expression, and induction of Nqo1, as well as other phase 2 genes. Activation of ERK1/2 has been demonstrated following treatment with D3T. While, inhibitors of p38, PKC and PI3K did not affect ARE-driven gene expression. Involvement of the ERK1/2 cascade in inducible ARE-transcription activities was also observed in cells treated with other types of inducers oltipraz, sulforaphane and hydrogen peroxide. Collectively, current study suggests that phosphorylation cascade via ERK1/2 is associated with the activation process of Nrf2 and subsequent transactivation of its target gene Nqo1 following treatment with dithiolethione in murine keratinocyte.

Direct surface force measurement in water using a nanosize colloidal probe technique

The direct force measurement between colloidal surfaces has been an essential topic in both theories and applications of surface chemistry. As particle size is decreased from micron size down to true nano size (<10 nm), surface forces are increasingly important. Nanoparticles at close proximity or high solids loading are expected to show a different behavior than what can be estimated from continuum and mean field theories. The current tools for directly measuring interaction forces such as a surface force apparatus or atomic force microscopy (AFM) are limited to particles much larger than nanosize. Here a modified colloidal probe technique is suggested using a multiwalled carbon nanotube (MWNT) to overcome this problem. Determination of zero separation in AFM is critical to extract a reliable force-separation curve when MWNT is used as a probe. Hence, a systematic approach to the data collection for a nanosize colloidal probe is proposed and a sample of a direct surface force measurement curve obtained with the MWNT probe is presented.

A diagnosis system for the spinal column nerve damaged patients

Visible evidence of spinal column damage is only apparent in 14% of the patients who receive spinal damage. We use a humidity sensor array. The humidity sensor (HDP-05) is arranged and attached to pre-assigned regions along the spinal column nerve of the actual patient. Applying pressure to the urinary bladder causes the patient to sweat. It is possible to determine which spinal column autonomic nerve is damaged in a region by humidity value. But also have some problem is that sometimes the damaged region has same value as a normal region. If will find a better attachment method and a more sensitive sensor could be found the results will be better and more precise.

Overexpression of SERTAD3, a putative oncogene located within the 19q13 amplicon, induces E2F activity and promotes tumor growth

The amplified region of chromosome 19q13.1-13.2 has been associated with several cancers. The well-characterized oncogene AKT2 is located in this amplicon. Two members of the same gene family (SERTAD1 and SERTAD3) are also located within this region. We report herein the genomic structure and potential functions of SERTAD3. SERTAD3 has two transcript variants with short mRNA half-lives, and one of the variants is tightly regulated throughout G1 and S phases of the cell cycle. Overexpression of SERTAD3 induces cell transformation in vitro and tumor formation in mice, whereas inhibition of SERTAD3 by small interfering RNA (siRNA) results in a reduction in cell growth rate. Furthermore, luciferase assays based on E2F-1 binding indicate that SERTAD3 increases the activity of E2F, which is reduced by inhibition of SERTAD3 by siRNA. Together, our data support that SERTAD3 contributes to oncogenesis, at least in part, via an E2F-dependent mechanism.

Phosphodiesterase: overview of protein structures, potential therapeutic applications and recent progress in drug development

Phosphodiesterases (PDEs) are essential regulators of cyclic nucleotide signaling with diverse physiological functions. Because of their great market potential and therapeutic importance, PDE inhibitors became recognized as important therapeutic agents in the treatment of various diseases. Currently, there are seven PDE inhibitors on the market, and the pharmacological and safety evaluations of many drug candidates are in progress. Three-dimensional (3D) structures of catalytic domains of PDE 1, -3, -4, -5 and -9 in the presence of their inhibitors are now available, and can be utilized for rational drug design. Recent advances in molecular pharmacology of PDE isoenzymes resulted in identification of new potential applications of PDE inhibitors in various therapeutic areas, including dementia, depression and schizophrenia. This review will describe the latest advances in PDE research on 3D structural studies, the potential of therapeutic applications and the development of drug candidates.

Folding and stability of sweet protein single-chain monellin. An insight to protein engineering

Engineered single-chain monellin (SCM) proteins were constructed by recombinant technology without disrupting the topology and sweet activity of native protein. Data from 8-anilinonaphthalene-1-sulfonic acid fluorescence, size-exclusion chromatography, and heteronuclear NMR strongly suggest the presence of a folding intermediate at 1.5 m GdnHCl for SCM protein. The structural feature of the folding intermediate from NMR data reveals that the secondary structures became mostly unstable, and protein experiences a dynamic equilibrium between native and unfolded state. All backbone amide protons exchange within 10 min, which imply that no stable hydrogen bonds exist in the secondary structural regions in the folding intermediate. From equilibrium unfolding and mutagenesis studies, the unfolding transition midpoints of mutant proteins gradually shifted toward lower denaturant concentration, indicating stability reductions of mutant proteins. Our results suggest that stability and folding pathways of SCM proteins could be regulated by a combined study of spectroscopy and mutagenesis, and these studies will provide useful information for understanding the folding kinetics of novel engineered proteins.

Detection of hepatocellular carcinoma: combined T2-weighted and dynamic gadolinium-enhanced MRI versus combined CT during arterial portography and CT hepatic arteriography

PURPOSE

The purpose of this study was to compare the preoperative detectability of hepatocellular carcinomas (HCCs) using combined T2-weighted and dynamic gadolinium-enhanced MRI and combined CT during arterial portography (CTAP) and CT hepatic arteriography (CTHA).

METHOD

Thirty-three patients with 43 HCCs underwent T2-weighted and dynamic gadolinium-enhanced MRI and combined CTAP and CTHA. The diagnosis was established by pathologic examination following surgical resection in 26 patients and by biopsy in 7 patients. The MR protocol included fast SE with two TEs (including T2-weighted imaging) and precontrast and gadolinium-enhanced T1-weighted fast multiplanar spoiled gradient-recalled echo images with dynamic study. The MR images of all sequences and the paired CTAP and CTHA images were independently reviewed by three radiologists. Image review was conducted on a segment-by-segment basis. Diagnostic accuracy was evaluated with receiver operating characteristic analysis.

RESULTS

The accuracies (Az values) of MRI of all sequences and combined CTAP and CTHA for all observers were 0.960 and 0.959, respectively. The mean sensitivities of MRI and CT were 90 and 94%, respectively. The differences were not statistically significant. The mean specificity of MRI (99%) was significantly higher than that of combined CTAP and CTHA (92%).

CONCLUSION

Combined T2-weighted and dynamic gadolinium-enhanced MRI is as accurate as combined CTAP and CTHA for preoperative detection of HCCs.

Solution structure, backbone dynamics, and stability of a double mutant single-chain monellin. structural origin of sweetness

Single-chain monellin (SCM), which is an engineered 94-residue polypeptide, has been characterized as being as sweet as native two-chain monellin. Data from gel-filtration high performance liquid chromatography and NMR has proven that SCM exists as a monomer in aqueous solution. In order to determine the structural origin of the taste of sweetness, we engineered several mutant SCM proteins by mutating Glu(2), Asp(7), and Arg(39) residues, which are responsible for sweetness. In this study, we present the solution structure, backbone dynamics, and stability of mutant SCM proteins using circular dichroism, fluorescence, and NMR spectroscopy. Based on the NMR data, a stable alpha-helix and five-stranded antiparallel beta-sheet were identified for double mutant SCM. Strands beta1 and beta2 are connected by a small bulge, and the disruption of the first beta-strand were observed with SCM(DR) comprising residues of Ile(38)-Cys(41). The dynamical and folding characteristics from circular dichroism, fluorescence, and backbone dynamics studies revealed that both wild type and mutant proteins showed distinct dynamical as well as stability differences, suggesting the important role of mutated residues in the sweet taste of SCM. Our results will provide an insight into the structural origin of sweet taste as well as the mutational effect in the stability of the engineered sweet protein SCM.

Non-combustible waste vitrification with plasma torch melter

Non-combustible radioactive wastes generated from Nuclear Power Plants (NPPs) are composed of concrete, glass, asbestos, metal, sand, soil, spent filters, etc. The melting tests for concrete, glass, sand, and spent filters were carried out using a 60 kW plasma torch system. The surrogate wastes were prepared for the tests. Non-radioactive Co and Cs were added to the surrogates in order to simulate the radioactive waste. Several kinds of surrogate prepared by their own mixture or by single waste were melted with the plasma torch system to produce glassy waste forms. The characteristics of glassy waste forms were examined for the volume reduction factor (VRF) and the leach rate. The VRFs were estimated through the density measurement of the surrogates and the glassy waste forms, and were turned out to be 1.2-2.4. The EPA (Environmental Protection Agency) Toxicity Characteristic Leaching Procedure (TCLP) was used to determine the leach resistance for As, Ba, Hg, Pb, Cd, Cr, Se, Co, and Cs. The leaching index was calculated using the total content of each element in both the waste forms and the leachant. The TCLP tests resulted in that the leach rates for all elements except Co and Cs were lower than those of the Universal Treatment Standard (UTS) limits. There were no UTS limits for Co and Cs, and their leach rate & index from the experiments were resulted in around 10 times higher than those of other elements.

Experimental and modeling evaluation of upward and downward velocities in the coaxial flotation column

This study was conducted to show the influence of upward velocity in the inner column and downward velocity in the outer column of the coaxial cylinder-type flotation column on the solids removal efficiency, solids concentration in the treated water, and so on. The SIMPLE (Semi-Implicit Method for Pressure Linked Equation) solution was applied to the coaxial flotation column to simulate the velocity vectors of the elements of water flowing in the column. The effects of solids loading and residence time in the agglomerate separation zone on the solids removal efficiency were also tested. In the pilot scale coaxial DAF column experiments with solids concentration of 1,000-2,000 mg of SS per liter and solids loading less than 350 kg/m2/day, approximately 90% of the solids removal efficiencies were obtained using the upward velocity of up to 110 cm/min in the contact zone of the inner column and the downward velocity of up to 30 cm/min in the outer column. In the simulation, similar results were observed as in the experiments. The solids loading in the excess of 350 kg/m2/day caused the instability of the sludge float layer and aggravated the quality of the treated water.

Expression and purification of an active, full-length hepatitis C viral NS4A

The nonstructural protein 3 (NS3) of the hepatitis C virus (HCV) is a bifunctional protein with protease and helicase activities. Nonstructural protein 4A (NS4A) is preceded by NS3 and augments the proteolytic activity of NS3 through protein-protein interaction. The central domain of NS4A has been shown to be sufficient for the enhancement of the NS3 protease activity. However, investigations on the roles of the N-terminal and the C-terminal regions of NS4A have been hampered by the difficulty of purification of full-length NS4A, a polypeptide that contains highly hydrophobic amino acid residues. Here we report a procedure by which one can produce and purify an active, full-length NS4A using maltose-binding protein fusion method. The full-length NS4A fused to the maltose binding protein is soluble and maintains its NS3 protease-enhancing activity.

RBT1, a novel transcriptional co-activator, binds the second subunit of replication protein A

Replication Protein A (RPA) is required for DNA recombination, repair and replication in all eukaryotes. RPA participation in these pathways is mediated by single-stranded DNA binding and protein interactions. We herein identify a novel protein, Replication Protein Binding Trans-Activator (RBT1), in a yeast two-hybrid assay employing the second subunit of human RPA (RPA32) as bait. RBT1-RPA32 binding was confirmed by glutathione S:-transferase pull-down and co-immunoprecipitation. Fluorescence microscopy indicates that green fluorescence protein-tagged RBT1 is localized to the nucleus in vivo. RBT1 mRNA expression, determined by semi-quantitative RT-PCR, is significantly higher in cancer cell lines MCF-7, ZR-75, SaOS-2 and H661, compared to the cell lines normal non-immortalized human mammary epithelial cells and normal non-immortalized human bronchial epithelial cells. Further, yeast and mammalian one-hybrid analysis shows that RBT1 is a strong transcriptional co-activator. Interestingly, mammalian transactivation data is indicative of significant variance between cell lines; the GAL4-RBT1 fusion protein has significantly higher transcriptional activity in human cancer cells compared to human normal primary non-immortalized epithelial cells. We propose that RBT1 is a novel transcriptional co-activator that interacts with RPA, and has significantly higher activity in transformed cells.

Needle-tract implantation in hepatocellular carcinoma: frequency and CT findings after biopsy with a 19.5-gauge automated biopsy gun

BACKGROUND

Needle-tract implantation is an important complication of cutting biopsy of hepatocellular carcinoma (HCC). This study was performed to evaluate the frequency of needle-tract implantation after ultrasound (US)-guided percutaneous biopsy of HCC and to describe triple-phase helical computed tomographic (CT) findings of implanted nodules.

METHODS

Between April 1994 and December 1997, 205 patients underwent US-guided percutaneous biopsy for HCC. Review of medical records and the pathology database disclosed seven patients who were found to have needle-tract implantation of HCC. Among these patients, five underwent triple-phase helical CT examination. We analyzed the frequency of needle-tract implantation and triple-phase helical CT findings of implanted nodules, with particular attention to the morphology and enhancement pattern.

RESULTS

Seven of 205 patients (3.4%) had tumor implantation along the needle tract at histologic examination after surgical resection. Eight implanted nodules in five patients were found on triple-phase helical CT images (one nodule in three patients, two nodules in one patient, and three nodules in one patient). All implanted nodules has well-circumscribed margins and were ovoid or lobulated in contour. On triple-phase helical CT, six (75%) implanted nodules were isodense compared with abdominal wall muscle on all triple-phase CTs, and two (25%) nodules were hyperdense on hepatic arterial and portal venous phases and isodense on equilibrium phase.

CONCLUSIONS

The frequency of needle-tract implantation of HCC after percutaneous needle biopsy was higher than reported previously, and careful attention should be paid during interpretation of CT images in patients with a history of previous percutaneous biopsy.

Dysplastic nodules in liver cirrhosis: evaluation of hemodynamics with CT during arterial portography and CT hepatic arteriography

PURPOSE

To evaluate the portal and arterial blood supplies to dysplastic nodules in the cirrhotic liver with computed tomography (CT) during arterial portography (CTAP) and CT hepatic arteriography (CTHA).

MATERIALS AND METHODS

Nineteen histopathologically proved low-grade dysplastic nodules and 13 high-grade dysplastic nodules in 17 patients with liver cirrhosis were evaluated with CTAP and CTHA for the presence of portal and arterial blood supplies to the nodules. The nodules ranged from 0.4 to 4.5 cm in diameter (mean, 1.6 cm).

RESULTS

The portal supply was present in 14 of the 19 (74%) low-grade dysplastic nodules and in seven of the 13 (54%) high-grade dysplastic nodules. The hepatic arterial supply was increased in four of the 19 (21%) low-grade dysplastic nodules, present in nine (47%), and absent in six (32%). The arterial supply was increased in four of the 13 (31%) high-grade dysplastic nodules, present in four (31%), and absent in five (38%).

CONCLUSION

The portal and arterial supplies to the low- and high-grade dysplastic nodules were variable and inconsistent. Therefore, it is difficult to detect and characterize the dysplastic nodules on the radiologic images on the basis of the blood supply.

Functional MR imaging of working memory in the human brain

OBJECTIVE

In order to investigate the functional brain anatomy associated with verbal and visual working memory, functional magnetic resonance imaging was performed.

MATERIALS AND METHODS

In ten normal right handed subjects, functional MR images were obtained using a 1.5-T MR scanner and the EPI BOLD technique. An item recognition task was used for stimulation, and during the activation period of the verbal working memory task, consonant letters were used. During the activation period of the visual working memory task, symbols or diagrams were employed instead of letters. For the post-processing of images, the SPM program was used, with the threshold of significance set at p <.001. We assessed activated brain areas during the two stimulation tasks and compared the activated regions between the two tasks.

RESULTS

The prefrontal cortex and secondary visual cortex were activated bilaterally by both verbal and visual working memory tasks, and the patterns of activated signals were similar in both tasks. The superior parietal cortex was also activated by both tasks, with lateralization to the left in the verbal task, and bilaterally without lateralization in the visual task. The inferior frontal cortex, inferior parietal cortex and temporal gyrus were activated exclusively by the verbal working memory task, predominantly in the left hemisphere.

CONCLUSION

The prefrontal cortex is activated by two stimulation tasks, and this is related to the function of the central executive. The language areas activated by the verbal working memory task may be a function of the phonological loop. Bilateral prefrontal and superior parietal cortices activated by the visual working memory task may be related to the visual maintenance of objects, representing visual working memory.

Salivary gland tumors: evaluation with two-phase helical CT

PURPOSE

To evaluate two-phase helical computed tomography (CT) in the characterization of salivary gland tumors.

MATERIALS AND METHODS

Sixty-four patients with major salivary gland tumors underwent two-phase helical CT. The histopathologic diagnosis was obtained by means of surgical resection or biopsy in all patients. After the injection of 90 mL of contrast material at a rate of 3 mL/sec, helical CT scans were obtained at early and delayed phases with scanning delays of 30 and 120 seconds, respectively. The attenuation change and enhancement patterns in the tumors were assessed. The attenuation change in the tumor also was assessed quantitatively as the ratio of the CT number (in Hounsfield units) at delayed phase scanning to that at early phase scanning.

RESULTS

There were 35 pleomorphic adenomas, nine Warthin tumors, and 20 malignant tumors. Two-phase helical CT showed increase in attenuation in 30 (86%) pleomorphic adenomas, decrease in eight (89%) Warthin tumors, and increase in 11 (55%) and no change in eight (40%) malignant tumors at delayed phase scanning. A multinodular enhancement pattern was found in only 12 (34%) pleomorphic adenomas. The ratio of CT numbers was significantly different between Warthin tumors and pleomorphic adenomas and between Warthin tumors and malignant tumors.

CONCLUSION

The analysis of enhancement patterns by using two-phase helical CT will be helpful in the differential diagnosis of salivary gland tumors.

Infantile fibromatosis in childhood: findings on MR imaging and pathologic correlation

AIM

The objective of this study was to analyse the MR imaging findings of infantile fibromatosis of childhood and to correlate them with histopathological features.

MATERIALS AND METHODS

Seven patients with histologically proven infantile fibromatosis were included in this study. The findings on MR images were retrospectively evaluated and then correlated with the pathological features. Findings on MR imaging evaluated included signal intensity, extent of hyperintense area on T2-weighted images, margins of the lesion, the degree and pattern of enhancement and the presence of fatty tissue. Pathological features evaluated included cellularity, collagenization, and myxoid change. A five point scale was used for the evaluation of the extent of hyperintense area on MR imaging, and each of pathological features.

RESULTS

On T1-weighted images, the lesions were iso-intense in two patients; iso- and hypointense in three; and iso-, hypo- and hyperintense in two. On T2-weighted images, iso-, hypo- and hyperintense areas were mixed in all patients, the hyperintense area being the largest portion of the lesion. The margins of the lesions were infiltrative in four patients (57%), smooth in two (29%) and mixed in one (14%). Enhancement was marked in five patients (72%) and diffuse in five (71%). Regardless of the hyperintense signal intensity on T2-weighted images, the grades of each pathologic feature were variable.

CONCLUSION

Infantile fibromatosis on MR imaging causes an enhancing mass, that is largely hyperintense on T2-weighted images. Areas of high signal intensity on T2-weighted images corresponded to variable grades of cellularity, collagenization, or myxoid change.

Primary mucinous cystadenocarcinoma of the appendix: CT findings

OBJECTIVE

The preoperative diagnosis of a primary appendiceal tumor can be difficult because of its rarity and the paucity of material in the radiology literature. The purpose of this study was to describe CT findings in six patients with primary mucinous cystadenocarcinoma of the appendix.

CONCLUSION

When CT reveals a cystic mass with enhancing wall nodularity in the expected area of the appendix, especially in older patients, the possibility of primary mucinous cystadenocarcinoma should be considered.

Variations in meniscofemoral ligaments at anatomical study and MR imaging

PURPOSE

To demonstrate variations in the meniscofemoral ligaments (ligaments of Wrisberg and Humphrey) at anatomical study and magnetic resonance (MR) imaging.

DESIGN

Twenty-eight cadaveric knees were partially dissected for the examination of the meniscofemoral ligaments. One hundred knee MR examinations were reviewed by two experienced musculoskeletal radiologists. Proximal variations in the meniscofemoral ligaments at MR imaging were classified into three types according to the attachment site: type I, medial femoral condyle; type II, proximal half of the posterior cruciate ligament (PCL); type III, distal half of the PCL. Distal variations were classified into vertical or oblique types according to the orientation of the intermediate signal at the interface of the ligament and lateral meniscus.

RESULTS

At anatomical study, six cases showed variations in the proximal insertion site of the meniscofemoral ligaments. At MR imaging 93 cases had one or more meniscofemoral ligaments, giving a total of 107 ligaments: 90 ligaments of Wrisberg and 17 ligaments of Humphrey. Forty-one ligaments of Wrisberg were type I, 28 type II, 19 type III, and with two indeterminate type, while 6 ligaments of Humphrey were type I and the remaining 11 were indeterminate. Seven cases showed no meniscofemoral ligament. Of the 107 meniscofemoral ligaments, the distal insertion orientation was of vertical type in 10 ligaments, oblique type in 70 and unidentified in 27.

CONCLUSION

An understanding of the high incidence of meniscofemoral ligament variations may help in the interpretation of knee MR studies.

Solution structure of a sweet protein single-chain monellin determined by nuclear magnetic resonance and dynamical simulated annealing calculations

Single-chain monellin (SCM), which is an engineered 94-residue polypeptide, has proven to be as sweet as native two-chain monellin. SCM is more stable than the native monellin for both heat and acidic environments. Data from gel filtration HPLC and NMR indicate that the SCM exists as a monomer in aqueous solution. The solution structure of SCM has been determined by nuclear magnetic resonance (NMR) spectroscopy and dynamical simulated annealing calculations. A stable alpha-helix spanning residues Phe11-Ile26 and an antiparallel beta-sheet formed by residues 2-5, 36-38, 41-47, 54-64, 69-75, and 83-88 have been identified. The sheet was well defined by backbone-backbone NOEs, and the corresponding beta-strands were further confirmed by hydrogen bond networks based on amide hydrogen exchange data. Strands beta2 and beta3 are connected by a small bulge comprising residues Ile38-Cys41. A total of 993 distance and 56 dihedral angle restraints were used for simulated annealing calculations. The final simulated annealing structures (<SA>k) converged well with a root-mean-square deviation (rmsd) between backbone atoms of 0.49 A for secondary structural regions and 0.70 A for backbone atoms excluding two loop regions. The average restraint energy-minimized (REM) structure exhibited root-mean-square deviations of 1.19 A for backbone atoms and 0.85 A for backbone atoms excluding two loop regions with respect to 20 <SA>k structures. The solution structure of SCM revealed that the long alpha-helix was folded into the concave side of a six-stranded antiparallel beta-sheet. The side chains of Tyr63 and Asp66 which are common to all sweet peptides showed an opposite orientation relative to H1 helix, and they were all solvent-exposed. Residues at the proposed dimeric interface in the X-ray structure were observed to be mostly solvent-exposed and demonstrated high degrees of flexibility.

A peptide from hog plasma that inhibits human cholesteryl ester transfer protein

A peptide that inhibits the human cholesteryl ester transfer protein (CETP) was isolated from hog plasma by ultracentrifugation, two sequential column chromatographies and electroelution from gels. Molecular weight of the peptide was determined to be approximately 3 kDa on the SDS-PAGE. The peptide contained 28 amino acids with an identical sequence to the amino terminus of hog apolipoprotein-CIII except two amino acid residues: -Pro-Glu- at the fifth and sixth amino acids from the amino terminus in the isolated peptide, in contrast to -Leu-Leu- in hog apo-CIII. A peptide synthesized chemically according to the amino acid sequence of the peptide (designated P28) showed approximately the same degree of CETP inhibitory activity as the isolated peptide. Synthetic peptides with different number of amino acids were also tested for CETP inhibition. Among the peptides, the one with 20 amino acid residues (P20) from the amino terminus showed the highest inhibitory activity against the CETP. The peptide appeared to be associated with the hog high-density lipoproteins (HDL), as determined by immunoblot analysis using antibody against P28. The CETP-inhibitory activity of the peptide was examined in vivo using diet-induced hypercholesterolemic rabbits. When the peptide was injected into the rabbits (7-9 mg/kg body weight), approximately 75% CETP activity disappeared from the plasma in 1 h after the injection and the effect lasted up to 30 h. The inhibition of CETP in vivo led to a concomitant decrease in total plasma cholesterol level up to 30% and an increase in the level of HDL-cholesterol up to 32%. The cholesterol concentrations in the rabbit plasma gradually recovered to the initial level after 48 h.

Molecular cloning of a novel ubiquitin-specific protease, UBP41, with isopeptidase activity in chick skeletal muscle

A cDNA encoding a new ubiquitin-specific protease, UBP41, in chick skeletal muscle was cloned using an Escherichia coli-based in vivo screening method. Nucleotide sequence analysis of the cDNA containing an open reading frame of 1,071 base pairs revealed that the protease consists of 357 residues with a calculated molecular mass of 40,847 Da, and is related to members of the UBP family containing highly conserved Cys and His domains. Chick UBP41 was expressed in E. coli and purified from the cells to apparent homogeneity, using 125I-labeled ubiquitin-alphaNH-MHISPPEPESEEEEEHYC as a substrate. The purified enzyme behaved as an approximately 43-kDa protein under both denaturing and nondenaturing conditions, suggesting that it consists of a single polypeptide chain. Like other deubiquitinating enzymes, it was sensitive to inhibition by ubiquitin-aldehyde and sulfhydryl blocking agents, such as N-ethylmaleimide. The UBP41 protease cleaved at the C terminus of the ubiquitin moiety in natural and engineered fusions irrespective of their sizes; thus, it is active against ubiquitin-beta-galactosidase as well as ubiquitin C-terminal extension protein of 80 amino acids. UBP41 also released free ubiquitin from poly-His-tagged di-ubiquitin. Moreover, it converted poly-ubiquitinated lysozyme conjugates to mono-ubiquitinated forms of about 24 kDa, although the latter molecules were not further degraded to free ubiquitin and lysozyme. These results suggest that UBP41 may play an important role in the recycling of ubiquitin by hydrolysis of branched poly-ubiquitin chains generated by the action of 26 S proteasome on poly-ubiquitinated protein substrates, as well as in the production of free ubiquitin from linear poly-ubiquitin chains and of certain ribosomal proteins from ubiquitin fusion proteins.

Effect of a novel saponin adjuvant derived from Quillaja saponaria on the immune response to recombinant hepatitis B surface antigen

Adjuvant activity of saponins extracted from the South American tree Quillaja saponaria has been demonstrated with many antigens. Recently, four saponin fractions (designated as QS-7, QS-17, QS-18, and QS-21) with adjuvant activity were purified by reverse phase chromatography. In particular, efficacy of the less toxic QS-21 fraction has been demonstrated with several recombinant viral antigens including HIV gp120. Here, we report a novel saponin fraction (designated as QS-L1) derived from Quillaja saponaria. Unlike previously identified saponins, QS-L1 had a different chemical structure and showed adjuvant activity only when administered in the presence of alum-precipitated antigen. Interestingly, the QS-L1 greatly increased not only a humoral immune response but also cellular immune response to recombinant hepatitis B virus surface antigen (HBsAg). Furthermore, QS-L1 showed lower toxicity in vivo and in vitro than the previously identified saponin fraction, QS-21. Finally, we examined the chemical structure of the QS-L1 using mass spectroscopic analysis, carbohydrate composition analysis and NMR spectroscopic analysis. Thus, our results indicated that this novel QS-L1 saponin fraction had several desirable properties required for an effective adjuvant.

Viral loads and E2/NS1 region sequences of hepatitis C virus in hepatocellular carcinoma and surrounding liver

OBJECTIVES

Numerous epidemiologic data have documented that chronic infection by hepatitis C virus (HCV) is a major risk factor for the development of hepatocellular carcinoma (HCC). But the molecular mechanism underlying these strong epidemiologic associations between HCV and HCC has not be elucidated. We observed the changes of HCV in HCC to investigate the association of HCV with HCC.

METHODS

We used competitive and quantitative polymerase chain reaction and dideoxy-nucleotide chain termination method to compare HCV titers and sequences of the hypervariable region of E2/NS1 region of four isolates from the HCC and surrounding cirrhotic liver tissues in tow anti-HCV positive patients.

RESULTS

The copy numbers of HCV-RNA were 1 x 10(6) and 4 x 10(6)/gm wet weight of HCC, and 8 x 10(7) and 3.2 x 10(8)/gm wet weight of cirrhotic liver tissues from patient-1 and -2. The sequence differences between HCV RNA in HCC and in cirrhotic liver were two and five nucleotides in patient-1 and in patient-2 respectively. The amino acid sequences were changed in one and two site in each patient.

CONCLUSION

These findings may suggest the possible etiological role of HCV in carcinogenesis of HCC, but complete sequence analysis of HCV including multiple isolates in the same patient, should be performed in many cases.

Spiral CT for the detection of hepatocellular carcinomas:relative value of arterial- and late-phase scanning

BACKGROUND

Spiral computed tomography (CT) can image the liver during arterial and late phases of contrast and optimize the evaluation of hypervascular tumor. The objective of this study was to evaluate the relative value of arterial- and late-phase spiral CT in the detection of hepatocellular carcinomas.

METHODS

Fifty-eight patients with hepatocellular carcinomas underwent two-phase spiral CT examination with 10-mm collimation at 10 mm/s table speed (Siemens Somatom Plus S), and 120 mL of contrast material (36 g iodine) was injected at the rate of 3 mL/s. CT images of hepatic arterial and late phases were obtained with a 35-s and 180-s delay, respectively.

RESULTS

In 58 patients, 111 hepatocellular carcinoma lesions were seen. The arterial phase detected 93 (84%) and the late phase 75 (68%) lesions (p < 0.01). The arterial phase detected more lesions in 11 patients, and the late phase detected more in two patients and an equal number in 45 patients. If lesions larger than 2 cm are excluded, the arterial phase detected 40 (74%) and the late phase 21 (39%) of 54 lesions (p < 0.001).

CONCLUSION

The arterial phase of spiral CT greatly improves the detection of hepatocellular carcinoma when compared with the late phase.

Non-major histocompatibility complex antigen class I-regulatory molecule for cytotoxicity by natural killer cells

The mechanism of the cytotoxicity by natural killer (NK) cells is not known. It is speculated that there exist several positively regulated and negatively regulated target molecules expressed on the target cell surface. Although one of the latter is considered to be major histocompatibility complex antigen (MHC) class I, in this study we described a novel non-MHC class I molecule that may negatively regulate the NK cytotoxicity. This antigen is defined by monoclonal antibody Cho-1 and is composed of noncovalently associated antigens that are 40 and 200 kilodaltons in molecular size. The expression of this antigen is reduced along with the cell growth induced by growth factors and/or oncogenes. Thus, Cho-1-defined antigen appears to be involved as one of the resistant molecules in the cytotoxic mechanism of NK cells.

Inhibition of natural killer cell cytotoxicity by cell growth-related molecules

Certain MHC class I molecules on target cells are known to inhibit the cytotoxic action of NK cells. By using monoclonal antibody (mAb) Cho-1, we have found inhibitory non-MHC class I cell surface molecules that are noncovalently-associated with 200 kDa and 40 kDa antigens. Poly I-C-induced rat NK cells were not cytotoxic to rat fetus-derived fibroblast WFB cell line. In contrast, NK cells were cytotoxic to H-ras oncogene-induced transformants of WFB, W14 and W31. FACS analysis indicated that mAb Cho-1 reacts with WFB, but not with W14 and W31 cells. Thus, this antigen may disappear concomitantly with cell growth and transformation. Cho-1 antigens were also expressed on other NK-resistant lines, such as mouse BALB3T3 fibroblast, EL-4 lymphoma and human fibroblast HEPM. However, they were not expressed on NK-sensitive mouse YAC-1 and H-ras transformant (Brash) of BALB3T3 cells. Furthermore, treatment of target cells with IFN-gamma clearly induced the cell surface expression of Cho-1 antigens, and conferred a resistance to NK cytolysis on target cells. These data strongly suggest that Cho-1 antigen expression may correlate with target cell susceptibility to NK cells. Indeed, treatment of NK-resistant WFB as well as HEPM cells with F(ab')2 fragments of mAb Cho-1 resulted in the acquisition of susceptibility to NK cytolysis. Cho-1 antigens may be novel molecules that regulate the NK resistance of cells.

Thermal response in murine L929 cells lacking alpha B-crystallin expression and alpha B-crystallin expressing L929 transfectants

We investigated the role of alpha B-crystallin expression in the development of thermotolerance in murine L929 cells. An initial heat-shock of 10 min at 45 degrees C induced thermotolerance in these cells to a heat challenge at 45 degrees C administered 24 h later. The thermotolerance ratio at 10(-1) isosurvival was 1.7. Expression of alpha B-crystallin gene was not detected during the 24 h incubation at 37 degrees C following heat shock by either northern or western blots. In contrast, inducible HSP70 synthesis was observed during this time period. Thus, this cell line provided an unique system in which to examine the effects of transfected alpha B-crystallin on thermoresistance and thermotolerance. Cells stably transfected with alpha B-crystallin under the control of an inducible promoter did not show a significant increase in the ability to develop thermotolerance. However, a stably transfected L929 clone expressing high levels of constitutive alpha B-crystallin exhibited an approximately 50% increase in thermal resistance over parental and control cells. Though expression of alpha B-crystallin is not requisite for the development of thermotolerance in L929 cells, overexpression of transfected alpha B-crystallin can contribute to increased thermoresistance.

Characterization of focal hepatic tumors. Value of two-phase scanning with spiral computed tomography

BACKGROUND

Spiral computed tomography (CT) allows imaging of the liver during the peak contrast material levels due to the capability of fast data acquisition. The objective of this study was to evaluate the usefulness of two-phase spiral CT in the differential diagnosis of focal hepatic tumors.

METHODS

One hundred two patients who had hepatic tumors (211 nodules; 149 hepatocellular carcinomas [HCCs], 36 metastases, and 26 hemangiomas) underwent two-phase spiral CT with 10-mm collimation at 10 mm/second table speed and 120 mL of contrast material injected at the rate of 3 mL/second. Computed tomography images of the hepatic arterial phase and late (equilibrium) phase were obtained at 35-second and 180-second delays, respectively. The enhancement patterns of tumors were divided into six types and were compared with the attenuation of surrounding liver parenchyma: totally high, peripherally high, centrally high, mixed, iso, and low.

RESULTS

The common enhancement patterns of HCC in two-phase spiral CT were totally high in the arterial phase and low (n = 63, 42%) or iso (n = 28, 19%) in the late phase. Metastasis showed peripherally nonnodular high attenuation (n = 9, 25%) or low attenuation (n = 9, 25%) in the arterial phase and low attenuation in the late phase, followed by totally high attenuation in the arterial phase and iso in the late phase (n = 6, 17%). Hemangiomas showed totally or peripherally nodular enhancement in the arterial and late phases (n = 23, 89%). In distinguishing hemangiomas from malignant tumors, totally high or peripherally nodular high attenuation in the late phase was the most useful contrast enhancement pattern (96% of hemangioma vs. 0% of malignant tumors). In distinguishing HCCs from metastases, a combination of contrast enhancement pattern of totally high attenuation in the arterial phase and low in the late phase was the most useful contrast enhancement pattern (42% of HCCs vs. 0% of metastases). The predictability of differentiation between hemangiomas and malignant tumors and between HCCs and metastases was 99% and 90% with spiral CT, respectively.

CONCLUSIONS

Two-phase spiral CT is useful in the differential diagnosis of focal hepatic tumors with evaluation of contrast enhancement patterns.

Differential effect of 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) on alpha B-crystallin and hsp70 gene expression in murine cell lines

We studied the effect of isoquinolinesulfonamide derivatives (H-7, H-8, and HA1004) on the expression of two heat shock genes (alpha beta-crystallin and hsp70) in NIH 3T3 and Swiss 3T3 cells after heat shock at 45 degrees for 10 min. Western blots and northern blots showed that H-7 effectively suppressed the accumulation of HSP70 and alpha B-crystallin mRNA as well as the synthesis of their proteins. The degree of suppression was dependent upon the concentration of the drug. Moreover, the expression of the hsp genes was differentially suppressed by H-7. The expression of the alpha B-crystallin gene was more effectively inhibited than that of the hsp70 gene by H-7. Nuclear run-on assay demonstrates that this difference was due to the differential effect of H-7 on the elongation of transcription of different hsp genes.

Association of hepatitis C virus particles with immunoglobulin: a mechanism for persistent infection

The physical properties of hepatitis C virus (HCV) particles were determined by ultracentrifugation on 20-60% isopycnic sucrose density gradients. We report that (i) two populations of HCV particles were found in the sera of patients with chronic HCV infection [at high density (1.186-1.213 g/ml) and at low density (1.099-1.127 g/ml)], (ii) virus particles with high density values were associated with immunoglobulin, and (iii) virus particles with low density values accumulated base changes within a hypervariable region (HVR) of the E2 envelope domain of the RNA genome. The results indicate that base changes within the HVR of E2 lead to the accumulation of immunoglobulin-free virus particles. Therefore, these findings imply that persistent HCV infection is established as a consequence of sequence variation in the E2 envelope domain.

Heat-induced bFGF gene expression in the absence of heat shock element correlates with enhanced AP-1 binding activity

Basic fibroblast growth factor (bFGF) has been shown to be a potent mitogen and a promoter of angiogenesis. It has been hypothesized that the expression of the bFGF gene may be induced by stress of various types. To test that hypothesis, we investigated the expression of the bFGF gene during heat treatment in adriamycin-resistant (MCF-7/ADR) and -sensitive (MCF-7) human breast carcinoma cells. Under normal growth conditions, the bFGF mRNA was detected in MCF-7/ADR cells, while it was not detectable in MCF-7 cells by Northern blot analysis. During heating at 41 degrees C, the level of bFGF mRNA increased in MCF-7/ADR cells and the message became detectable in the MCF-7 cell line. However, after continuous heating at 41 degrees C for 24 h, the bFGF mRNA level decreased to control level in MCF-7/ADR cells. Interestingly, simultaneous treatment with heat and 60 micrograms/ml H-7 (1-(isoquinolinylsulfonyl)-2-methylpiperazine, a potent PKC inhibitor) decreased the level of bFGF mRNA in MCF-7/ADR cells. These results suggest that a protein kinase, likely PKC, is involved in the transcriptional regulation of the heat-enhanced bFGF gene expression in human breast carcinoma cells. Although no heat shock element can be identified in the promoter of the bFGF gene, we observed that the AP-1 binding activity to a TPA responsive element (TRE)-like sequence in the promoter of bFGF gene was enhanced by heat, as tested by mobility shift assay. Antibody developed against the c-Jun and c-Fos proteins inhibited the AP-1 binding activity to TRE. Therefore, the AP-1 complex appears to be responsible for the heat-enhanced binding to the TRE-like motif of the bFGF gene. Furthermore, the increased AP-1 binding activity does not require new protein synthesis but activation of the preexisting c-Jun proteins.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cystic peripheral cholangiocarcinoma: sonography and CT

A case of cystic peripheral cholangiocarcinoma is presented. Both sonography and computed tomography (CT) demonstrated a large intrahepatic cystic neoplasm containing an enhancing solid portion. Despite the very rare incidence of this tumor, we believe that cystic degeneration of peripheral cholangiocarcinoma should be considered with these radiologic findings.

The taste-active regions of monellin, a potently sweet protein

Monellin, a protein found in the berries of the West African plant Dioscoreophyllum cumminsii, is one of the most potently sweet compounds known. The native three-dimensional structure of monellin is required for sweetness, and this protein has been the subject of intense research in an attempt at understanding the structural basis for its taste activity. We have used structure-based site-directed mutagenesis to delineate the taste-active site(s) of monellin, and we present these results, along with similar work from M. Kohmura, Y. Ariyoshi and coworkers, in the light of the three-dimensional structure of this protein. The mutagenesis work suggests that at least four residues, located N-terminal to the alpha-helix, form part of a taste-active region of monellin. In addition, there is evidence that a second region, formed by residues in the fourth and fifth beta-strands, may also be contributing to monellin's activity.

Response of serum cytokines in patients undergoing laparoscopic cholecystectomy

The clinical observation that a laparoscopic cholecystectomy is a minimally invasive operation has not been demonstrated on a biochemical basis. Interleukin-6, a known endogenous pyrogen and hepatocyte-stimulating protein, correlates with the significance of surgical trauma. Utilizing the IL-6 immunoassay, we studied this biochemical parameter of trauma to compare its response in laparoscopic vs open cholecystectomy. Sixteen patients who underwent only laparoscopic cholecystectomy showed peak IL-6 concentrations of 51 pg/ml (22-86) vs a peak IL-6 concentration of 124 pg/ml (56-225) for open cholecystectomy. Six additional patients who underwent an ERCP followed by laparoscopic cholecystectomy showed a dramatic rise in peak IL-6 concentration to 315 pg/ml (15-634). These results biochemically confirm the true minimal invasiveness of laparoscopic cholecystectomy. The findings in the ERCP-followed-by-laparoscopic-cholecystectomy group support the theory that two invasive procedures in close proximity may prime the cytokine system in its response to surgical trauma.