Electrophoresis, a transport technology that transitioned from moving boundary method to zone method

Gel electrophoresis, a transport technology, is one of the most widely used experimental methods in biochemical and pharmaceutical research and development. Transport technologies are used to determine hydrodynamic or electrophoretic properties of macromolecules. Gel electrophoresis is a zone technology, where a small volume of sample is applied to a large separation gel matrix. In contrast, a seldom-used electrophoresis technology is moving boundary electrophoresis, where the sample is present throughout the separation phase or gel matrix. While the zone method gives peaks of separating macromolecular solutes, the moving boundary method gives a boundary between solute-free and solute-containing phases. We will review electrophoresis as a transport technology of zone and moving boundary methods and describe its principles and applications.

Development of a novel two-dimensional gel electrophoresis protocol with agarose native gel electrophoresis

A new protocol for conducting two-dimensional (2D) electrophoresis was developed by combining the recently developed agarose native gel electrophoresis with either vertical sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) or flat SDS agarose gel electrophoresis. Our innovative technique utilizes His/MES buffer (pH 6.1) during the first-dimensional (1D) agarose native gel electrophoresis, which allows for the simultaneous and clear visualization of basic and acidic proteins in their native states or complex structures. Our agarose gel electrophoresis is a true native electrophoresis, unlike blue native-PAGE, which relies on the intrinsic charged states of the proteins and their complexes without the need for dye binding. In the 2D, the gel strip from the 1D agarose gel electrophoresis is soaked in SDS and placed on top of the vertical SDS-PAGE gels or the edge of the flat SDS-MetaPhor high-resolution agarose gels. This allows for customized operation using a single electrophoresis device at a low cost. This technique has been successfully applied to analyze various proteins, including five model proteins (BSA, factor Xa, ovotransferrin, IgG, and lysozyme), monoclonal antibodies with slightly different isoelectric points, polyclonal antibodies, and antigen-antibody complexes, as well as complex proteins such as IgM pentamer and β-galactosidase tetramer. Our protocol can be completed within a day, taking approximately 5-6 h, and can be expanded further into Western blot analysis, mass spectrometry analysis, and other analytical methods.

Elucidating the mechanisms of additive effects at high concentrations on hydrophobic interaction chromatography

Hydrophobic interaction chromatography (HIC) is a commonly used chromatography technique for purifying proteins. It utilizes salting-out salts to facilitate the binding of native proteins to weakly hydrophobic ligands. There have been three proposed mechanisms for the promoting effects of salting-out salts, which include the dehydration of proteins by salts, cavity theory, and salt exclusion. To evaluate the above three mechanisms, an HIC study was conducted on Phenyl Sepharose using four different additives. These additives included a salting-out salt (NH₄)₂SO₄, sodium phosphate that increases the surface tension of water, a salting-in salt MgCl₂, and an amphiphilic protein-precipitant polyethylene glycol (PEG). Results indicated that the first two salts resulted in protein binding, while MgCl₂ and PEG led to flow-through. These findings were then used to interpret the three proposed mechanisms, which showed that MgCl₂ and PEG deviated from the dehydration mechanism, and MgCl₂ also deviated from the cavity theory. The observed effects of these additives on HIC were reasonably well explained for the first time by their interactions with proteins.

Non-Affinity Purification of Antibodies

Currently, purification of antibodies is mainly carried out using a platform technology composed primarily of Protein A chromatography as a capture step, regardless of the scale. However, Protein A chromatography has a number of drawbacks, which are summarized in this review. As an alternative, we propose a simple small-scale purification protocol without Protein A that uses novel agarose native gel electrophoresis and protein extraction. For large-scale antibody purification, we suggest mixed-mode chromatography that can in part mimic the properties of Protein A resin, focusing on 4-Mercapto-ethyl-pyridine (MEP) column chromatography.

Detection of concentration-dependent conformational changes in SARS-CoV-2 nucleoprotein by agarose native gel electrophoresis

The nucleoprotein (NP) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is abundantly expressed during infection, making it a diagnostic target protein. We analyzed the structure of the NP in solution using a recombinant protein produced in E. coli. A codon-optimized Profinity eXact™-tagged NP cDNA was cloned into pET-3d vector and transformed into E. coli T7 Express. The recombinant protein was first purified via chromatographic step using an affinity tag-based system that was followed by tag cleavage with sodium fluoride, resulting in proteolytic removal of the N-terminal tag sequence. The digested sample was then loaded directly onto a size exclusion chromatography run in the presence of L-Arg-HCl, resulting in removal of host nucleic acids and endotoxin. The molecular mass of the main NP fraction was determined by mass photometry as a dimeric form of NP, consistent with the blue native PAGE results. Interestingly, analysis of the purified NP by our newly developed agarose native gel electrophoresis revealed that it behaved like an acidic protein at low concentration despite its alkaline isoelectric point (theoretical pI = 10) and displayed a unique character of concentration-dependent charge and shape changes. This study should shed light into the behavior of NP in the viral life cycle.

Analysis of bovine serum albumin unfolding in the absence and presence of ATP by SYPRO Orange staining of agarose native gel electrophoresis

An attempt was made to specifically stain unfolded proteins on agarose native gels. SYPRO Orange is routinely used to detect unfolded protein in differential scanning fluorimetry, which is based on the enhanced fluorescence intensity upon binding to the unfolded protein. We demonstrated that this dye barely bound to the native proteins, resulting in no or faint staining of the native bands, but bound to and stained the unfolded proteins, on agarose native gels. Using bovine serum albumin (BSA), it was shown that staining did not depend on whether BSA was thermally unfolded in the presence of SYPRO Orange or stained after electrophoresis. On the contrary, SYPRO Orange dye stained protein bands in the presence of sodium dodecylsulfate (SDS) due to incorporation of the dye into SDS micelles that bound to the unfolded proteins. This staining resulted in detection of new, intermediately unfolded structure of BSA during thermal unfolding. Such intermediate structure occurred at higher temperature in the presence of ATP.

Gel-electrophoresis based method for biomolecular interaction

Electrophoresis is one of the most important analytical technologies for characterization of macromolecules and their interactions. Among them, native gel electrophoresis is used to analyze the macromolecules in the native structure. It differs in principle and information from those obtained by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) or blue native polyacrylamide gel electrophoresis (BN-PAGE). SDS-PAGE is carried out in the presence of strong denaturant, SDS, while BN-PAGE is done in the presence of negatively charged dye, e.g., Coomassie brilliant blue, G-250. Here, we describe native gel electrophoresis using agarose gel and a buffer at pH 6.1 composed of histidine and 2-(N-morpholino) ethanesulfonic acid. First, a protocol for vertical and horizontal formats of agarose native gel electrophoresis is described followed by different staining procedures. Then, various examples obtained using the developed procedure will be shown to demonstrate how the technology can be applied to specific cases and the advantages or caveats of the present technology.

Western blotting of native proteins from agarose gels

We have developed a new Western blotting method of native proteins from agarose-based gel electrophoresis using a buffer at pH 6.1 containing basic histidine and acidic 2-(N-morpholino)ethanesulfonic acid. This gel electrophoresis successfully provided native structures for a variety of proteins and macromolecular complexes. This paper is focused on the Western blotting of native protein bands separated on agarose gels. Two blotting methods from agarose gel to PVDF membrane are introduced here, one by contact (diffusion) blotting and another by electroblotting after pre-treating the agarose gels with SDS. The contact blotting resulted in the transfer of native GFP, native human plexin domain containing protein 2 (PLXDC2) and native SARS-CoV-2 spike protein, which were detected by conformation-specific antibodies generated in-house.

A rabbit monoclonal antibody-mediated lateral flow immunoassay for rapid detection of CTX-M extended-spectrum β-lactamase-producing Enterobacterales

Infections of CTX-M extended-spectrum β-lactamase-producing Enterobacterales are a severe threat in clinical settings. CTX-M genes on plasmids have been transferred to many Enterobacterales species, and these species have spread, leading to the global problem of antimicrobial resistance. Here, we developed a lateral flow immunoassay (LFIA) based on an anti-CTX-M rabbit monoclonal antibody. This antibody detected CTX-M variants from the CTX-M-9, CTX-M-2, and CTX-M-1 groups expressed in clinical isolates. The LFIA showed 100% sensitivity and specificity with clinical isolates on agar plates, and its limit of detection was 0.8 ng/mL recombinant CTX-M-14. The rabbit monoclonal antibody did not cross-react with bacteria producing other class A β-lactamases, including SHV. In conclusion, we developed a highly sensitive and specific LFIA capable of detecting CTX-M enzyme production in Enterobacterales. We anticipate that our LFIA will become a point-of-care test enabling rapid detection of CTX-M in hospital and community settings as well as a rapid environmental test.

Cumulative incidence of femoral localized periosteal thickening (beaking) preceding atypical femoral fractures in patients with rheumatoid arthritis

The incidence of localized periosteal thickening (LPT, also termed beaking) of the lateral cortex that often precedes an atypical femoral fracture (AFF) was not high in patients with rheumatoid arthritis (RA) but incomplete AFFs developed in two patients. Higher-dose prednisolone was a significant risk factor for LPT in patients with RA.

INTRODUCTION

Atypical femoral fractures (AFFs) are stress fractures; bisphosphonate (BP) use is a major risk factor for the development of such fractures. Localized periosteal thickening (LPT, also termed beaking) of the lateral cortex often precedes a complete or incomplete AFF. We evaluated the incidence of latent LPT in patients with rheumatoid arthritis (RA), to evaluate LPT progression, and to define LPT risk factors.

METHODS

A total of 254 patients with RA were included; all underwent annual X-ray evaluation, dual-energy X-ray absorptiometry, and analyses of serum and bone metabolic markers for 2-3 years. LPT of the lateral cortex was sought in femoral X-rays.

RESULTS

The incidence of LPT was 2.4% (6/254). Among patients on both BP and prednisolone (PSL) at enrollment, the incidence was 2.3% (3/131). Two femurs of two patients with LPT developed incomplete AFFs; LPT was extensive and associated with endosteal thickening. One patient had been on BP and PSL and microscopic polyangiitis was comorbidity. The other was on a selective estrogen receptor modulator and PSL. A daily PSL dose >5 mg (OR 11.4; 95%CI 2.15-60.2; p = 0.004) and higher-dose methotrexate (OR 1.22; 95%CI 1.01-1.49; p = 0.043) were significant risk factors for LPT.

CONCLUSIONS

The incidence of latent LPT was not high (2.4%) but incomplete AFFs developed in two RA patients. Higher-dose PSL because of a comorbid disease requiring glucocorticoid treatment other than RA or refractory RA were risk factors for LPT; X-ray screening for latent LPT would usefully prevent complete AFFs.

Analysis of protein denaturation, aggregation and post-translational modification by agarose native gel electrophoresis

Agarose native gel electrophoresis has been developed to separate proteins and protein complexes in the native state. Here, we applied this technology to analyze proteins that undergo degradation, post-translational modification or chemical/physical changes. Antibodies showed aggregation/association upon acid or heat treatment. Limited reduction of disulfide bonds resulted in non-covalent aggregation of bovine serum albumin and cleavage of only inter-chain linkages of an antibody that had no effects on its overall structure. Native agarose gel analysis showed changes in mobility of human transferrin upon Fe³⁺ binding. Analysis of a commercial glycated human hemoglobin A1c showed no difference in electrophoretic pattern from un-modified hemoglobin. Native agarose gel showed aggregation of a virus upon acid or heat treatment. We have extracted bands of bovine serum albumin from the agarose native gel for sodium dodecylsulfate gel electrophoresis analysis, showing degradation of aged sample. Lastly, we analyzed phosphorylation of Zap70 kinase by native gel and Western blotting. These applications should expand the utility of this native gel electrophoresis technology.

AB0297 THE LONG-TERM OBSERVATION OF PATIENTS WITH RHEUMATOID ARTHRITIS WHO ACHIEVED A BIO-FREE CONDITION WITH ADALIMUMAB

Background:

Biological disease-modifying antirheumatic drugs (bDMARDs) caused a paradigm shift in the treatment of rheumatoid arthritis (RA). However, their high cost is a burden for patients and the national medical economy.

Objectives:

To analyze the long-term outcomes of patients with RA who achieved a bio-free condition (BF) with adalimumab (ADA).

Methods:

We followed 25 patients (male 6, female 19) who discontinued ADA with clinical remission (CR), and one female with a low disease activity (LDA), over 19.4 ±7.8 months of ADA treatment1). At the introduction of ADA, the average age was 51.2 ± 11.9 years old, and the average disease duration was 45.1 ± 48.4 months. The disease activity measured by disease activity score based on C-reactive protein (DAS28-CRP) was defined as follows: CR, <2.3; LDA, 2.3 - 2.7; moderate DA, 2.7 -4.1; and high DA, > 4.1, since the DAS28-CRP tends to be lower than the DAS28-based on the erythrocyte sedimentation rate in Japanese patients2).

Results:

We lost one patient with a transfer to another hospital. Four patients re-started ADA due to flare (DAS28-CRP>2.7) but achieved CR (in BF) again with the intensification of the treatment (dose increase or initiation of prednisolone [PSL] and/or conventional synthetic [cs] DMARDs such as tacrolimus or iguratimode). The DAS28-CRP significantly decreased from 3.45 ± 1.32 at base line (BL) to 1.55 ± 0.41 (p<0.0001) at BF. It remained 1.59 ± 0.59 (n=25) at 24 months after BF, 1.56 ± 0.39 (n= 20) at 48 months, 1.8 ± 0.7 (n=11) at 60 months. At the last observation, every patient remained in CR up to 84 months (n=2, Figure 1). The modified health assessment questionnaire score significantly decreased from 0.42 ± 0.46 (BL, n=19) to 0.02 ± 0.05 (p<0.002) at BF. It remained 0.03 ± 0.07 (n=19) at 24 months and 0.06 ± 0.14 (n=14) at 48 months, 0.04 ± 0.08 at 60 months (n=9). The PSL dose (mg/day) decreased from 3.2 ± 3.3 (BL) to 2.2 ± 2.8 at BF and 2.04 ± 2.13 (n=25) at 24 months, 1.73 ± 1.9 (n=20) at 48 months, and 1.6 ± 2.3 (n=11) at 60 months, but there were no significant changes. The methotrexate (MTX) dose (mg/week) increased from 10.1 ± 2.9 (BL) to 10.6 ± 2.6 (p< 0.78) at BF, 10.4 ± 3.3 (n=25) at 24 months, 10.7 ± 3.4 (n=20) at 48 months, 10.4 ± 3.1 at 60 months (not significant). The number of csDMARDs significantly increased from 0.8 ± 0.6 (BL) to 1.3 ± 0.9 (p<0.001, at BF), 2.56 ± 0.94 (n=25) at 24 months, 1.6 ± 1.01 (n=20) at 48 mnths, and 1.6 ± 2.3 at 60 months (n=11, Figure 2).

Conclusion:

BF can be sustained with an adequate dose of MTX and combination of csDMARDs.

References:

[1]Ito S, et al. An analysis of the biological disease-modifying antirheumatic drug-free condition of adalimumab-treated rheumatoid arthritis patients. Intern Med 58: 511-519, 2019

[2]Inoue E, et al. Comparison of Disease Activity Score (DAS)28-erythrocyte sedimentation rate and DAS28- C-reactive protein threshold values. Ann Rheum Dis. 66:407-409, 2007.

Disclosure of Interests:

Satoshi Ito Speakers bureau: Abbvie,Eisai, Shunsuke sakai: None declared, Yoichi Kurosawa: None declared, Daisuke Kobayashi: None declared, Ryo Okabayashi: None declared, Asami Abe: None declared, Hiroshi Otani: None declared, Kiyoshi Nakazono: None declared, Akira Murasawa: None declared, Ichiei Narita: None declared, Hajime Ishikawa: None declared

Tendency for Interlaboratory Precision in the GMO Analysis Method Based on Real-Time PCR

The Horwitz curve estimates interlaboratory precision as a function only of concentration, and is frequently used as a method performance criterion in food analysis with chemical methods. The quantitative biochemical methods based on real-time PCR require an analogous criterion to progressively promote method validation. We analyzed the tendency of precision using a simplex real-time PCR technique in 53 collaborative studies of seven genetically modified (GM) crops. Reproducibility standard deviation (SR) and repeatability standard deviation (Sr) of the genetically modified organism (GMO) amount () was more or less independent of GM crops (i.e., maize, soybean, cotton, oilseed rape, potato, sugar beet, and rice) and evaluation procedure steps. Some studies evaluated whole steps consisting of DNA extraction and PCR quantitation, whereas others focused only on the PCR quantitation step by using DNA extraction solutions. Therefore, SR and Sr for GMO amount () are functions only of concentration similar to the Horwitz curve. We proposed SR 0.1971C0.8685 and Sr 0.1478C0.8424, where C is the GMO amount (). We also proposed a method performance index in GMO quantitative methods that is analogous to the Horwitz Ratio.

Qualitative PCR Method for Roundup Ready® Soybean: Interlaboratory Study

Quantitative and qualitative methods based on PCR have been developed for genetically modified organisms (GMO). Interlaboratory studies were previously conducted for GMO quantitative methods; in this study, an interlaboratory study was conducted for a qualitative method for a GM soybean, Roundup Ready® soy (RR soy), with primer pairs designed for the quantitative method of RR soy studied previously. Fourteen laboratories in Japan participated. Each participant extracted DNA from 1.0 g each of the soy samples containing 0, 0.05, and 0.10% of RR soy, and performed PCR with primer pairs for an internal control gene (Le1) and RR soy followed by agarose gel electrophoresis. The PCR product amplified in this PCR system for Le1 was detected from all samples. The sensitivity, specificity, and false-negative and false-positive rates of the method were obtained from the results of RR soy detection. False-negative rates at the level of 0.05 and 0.10% of the RR soy samples were 6.0 and 2.3%, respectively, revealing that the LOD of the method was somewhat below 0.10%. The current study demonstrated that the qualitative method would be practical for monitoring the labeling system of GM soy in kernel lots.

Isolation of human monoclonal antibodies that bind to two different antigens and are encoded by germline VH and VL genes

This paper reports isolation of two monoclonal antibodies (mAbs) that bind to both a membrane protein and a cytoplasmic protein. Most Abs established as markers for autoimmune disease bind to cytoplasmic or nuclear substances. However, it remains unknown how these Abs are produced. On the other hand, there were examples where clones originally isolated as Abs that bind to membrane proteins also showed binding activity to cytoplasmic or nuclear substances. Based on these results, the following hypothesis has been proposed. The Abs that had been originally produced against a membrane protein showed cross-reactivity against cytoplasmic or nuclear substances. In the present study we reported isolation of Abs that bound to both a membrane protein, CADM1, and a cytoplasmic protein, α-actinin-4. The method adopted in the present study could be generally applicable to isolation of Abs showing such dual specificity. Firstly, we constructed a huge human Ab library using various organs including naïve B-cell-rich organs such as bone marrow and umbilical cords. Then, we developed a comprehensive screening method for isolation of Abs that bound to cell surface antigens. Through extensive screenings with many kinds of cell we newly obtained a library composed of around 4000 independent clones that bind to membrane proteins. We screened this library with α-actinin-4 and succeeded in isolating two Abs. They bound to α-actinin-4 and a membrane protein CADM1. Furthermore, they are encoded by naïve heavy and light chain variable genes (V_H & V_L). These results suggested that cross-reactive Abs to both a membrane protein and a cytoplasmic protein could be present in germline repertoire of Ab in humans. This methodology adopted in the present study could be applied to isolation of cross-reactive Abs possibly involved in autoimmune diseases.

Biophysical characterization of a model antibody drug conjugate

Antibody drug conjugates (ADC) are important next-generation biopharmaceuticals and thus require stringent structure characterization as is the case for monoclonal antibodies. We have tested several biophysical techniques, i.e., circular dichroism, analytical ultracentrifugation, differential scanning calorimetry and fluorescence spectroscopy, to characterize a fluorescein-labeled monoclonal antibody as a model ADC. These techniques indicated possible small structure and stability changes by the conjugation, while largely retaining the tertiary structure of the antibody, consistent with unaltered biological activities. Thus, the above biophysical techniques are effective at detecting changes in the structural properties of ADC.

Planned Overreaching and Subsequent Short-term Detraining Enhance Cycle Sprint Performance

We investigated the effect of a training program consisting of planned overreaching and subsequent short-term detraining on sprint performance. 24 physically active men participated in an 18-day sprint-training program. They were divided into 2 groups: the overreaching-detraining (OR-DT) and the control (CON) groups. Subjects in the OR-DT group performed 12 consecutive days of maximal cycle sprint training followed by 6 days of detraining, whereas a rest day was provided after every 2 successive training days for the CON group. Peak power output during maximal pedaling increased significantly after 6 days of detraining in the OR-DT group compared with the baseline (P<0.05), whereas no change was observed in CON group. Intramuscular phosphocreatine concentration increased significantly after 12 days of daily training in the OR-DT group (69.3±45.8% increase vs. baseline, P<0.05), and it was maintained after the detraining period (46.6±33.6% increase vs. baseline, P<0.05). However, no change was observed in CON group. No significant changes in blood variables were observed after the training period except significant reduction of serum cortisol in the CON group. Daily sprint training and subsequent short-term detraining enhanced peak power output after the detraining period.

Decreased infarct volume and intracranial hemorrhage associated with intra-arterial nonionic iso-osmolar contrast material in an MCA occlusion/reperfusion model

BACKGROUND AND PURPOSE

Infarct volume and intracranial hemorrhage after reperfusion with nonionic low-osmolar and iso-osmolar iodinated IRCM has not been previously compared. We postulated that iso-osmolar and low-osmolar iodinated contrast media exert varied effects on cerebral infarct after intra-arterial injection. We compared infarct volume and hemorrhagic changes following intra-arterial infusion of iodixanol, iopamidol, or normal saline in a rat MCA occlusion/reperfusion model.

MATERIALS AND METHODS

Infarct was induced in 30 rats by a previously validated method of MCA suture occlusion. Reperfusion was performed after 5 hours with either iodixanol (n = 9), iopamidol (n = 12), or saline (n = 9). MR images were obtained at both 6 and 24 hours after ischemia, followed by sacrifice. Infarct volume was measured with T2WI and DWI by semiautomatic segmentation. Incidence and area of hemorrhage were measured on brain sections postmortem.

RESULTS

T2WI mean infarct volumes were 242 ± 89, 324 ± 70, and 345 ± 92 mm(3) at 6 hours, and 341 ± 147,470 ± 91, and 462 ± 71 mm(3) at 24 hours in the iodixanol, iopamidol, and saline groups, respectively. Differences in infarct volume among groups were significant at 6 hours (P < .03) and 24 hours (P < .05). In the iodixanol, iopamidol, and saline groups, mean areas for cortical intracranial hemorrhage were 0.8, 18.2, and 25.7 mm(2); and 28, 31, and 56.7 mm(2), respectively, for deep intracranial hemorrhage. The differences in intracranial hemorrhage area among groups were statistically significant for cortical intracranial hemorrhage (P < .01).

CONCLUSIONS

Intra-arterial infusion of nonionic iso-osmolar iodixanol showed reduced infarct volume and reduced cortical intracranial hemorrhage areas in comparison with nonionic low-osmolar iopamidol and saline. Our results may be relevant in the setting of intra-arterial therapy for acute stroke in humans, warranting further investigation.

Influence of losartan intake on the circadian rhythm of melatonin secretion in humans

It has been reported that losartan, an angiotensin II receptor blocker, alters the circadian rhythm of melatonin secretion and significantly reduces melatonin production. However, this finding has been confirmed at the animal experiment level only, and there are no reports of studies in humans. Therefore, we performed this study to confirm the reproducibility of the aforementioned findings of animal experiments in humans. Ten male subjects who were in good general health and free from any medical condition were recruited for this study. After a preliminary observation period of 7 days, the subjects received oral losartan treatment, 50 mg daily for 7 days. Blood samplings for measurement of the plasma melatonin concentrations were performed on day 7 of the preliminary observation period and day 7 of the losartan treatment period. The circadian rhythm of melatonin secretion after the 7-day treatment with losartan showed no significant difference from that recorded before the losartan administration. The significant decrease of the home blood pressure was observed on the afternoons. The blood samples showed significant decrease of the serum sodium and uric acid levels, along with a significant increase of the serum potassium level. The pharmacological actions of losartan at the ordinarily used clinical dose level were confirmed in humans, however, no significant inhibitory effect of the drug on melatonin secretion could be confirmed. These results are expected to be useful for guiding the proper use of angiotensin II receptor blockers.

Treatment of high-risk solid tumors of childhood with myeloablative chemotherapy and autologous stem cell transplantation

Sixteen consecutive stem cell transplantations (SCT) were performed after myeloablative chemotherapy in patients with high-risk solid tumors of childhood. Seven patients received autologous bone marrow transplantation (ABMT), seven received peripheral blood stem cell transplantation (PBSCT) and two received ABMT + PBSCT. The progression-free survival was similar in three types of transplants (57% ABMT, 43% PBSCT vs. 50% ABMT + PBSCT). The rate of relapse in site of distant organs was also similar (57% ABMT, 57% PBSCT vs. 50% ABMT + PBSCT). There was no statistically significant difference in the hematopoietic recovery time between each group. PBSCT group had a significantly fewer days of food intolerance and a lower morbidity than ABMT group. The disease-free survival was 71% for neuroblastoma, 50% for small round cell tumors and 25% for rhabdomyosarcoma. Post-SCT therapy for possible reinfused tumor cells should be mandatory to decrease the frequency of relapse.

Matrix metalloproteinase-2 or -9 deletions protect against hemorrhagic transformation during early stage of cerebral ischemia and reperfusion

MMP-9 deficiency protected against photochemical thrombosis-induced brain hemorrhagic transformation (HT), but it did not protect against tissue plasminogen activator-induced brain hemorrhage. The roles of MMP-2 and/or MMP-9 knockout (KO) in mechanical reperfusion induced HT after ischemia have not been investigated. Here we assessed the effects of MMP-2 KO, MMP-9 KO and MMP-2/9 double KO (dKO) in protecting against mechanical reperfusion induced HT and other brain injuries after the early stages of cerebral ischemia in mice of the same genetic background. Middle cerebral artery occlusion (MCAO) was performed in mice. Reperfusion was started at 1 or 1.5h after onset of MCAO. All mice were sacrificed 8h after MCAO. We found that both pro- and active MMP-2 and MMP-9 levels were significantly elevated in the early ischemic brain. After the early stages of ischemia and reperfusion, the hemorrhagic incidence was reduced in the cortex of MMP-2 KO mice (p<0.05 vs. WT). The hemorrhagic volume was significantly decreased in the cortexes of MMP-2 and/or -9 knockout mice (MMP-9 KO vs. WT: p<0.01, MMP-2 KO and dKO vs. WT: p<0.001). In the basal ganglia, MMP-2 KO and MMP-2/9 dKO mice displayed a remarkable decrease in hemorrhagic volume (p<0.01 or 0.05 vs. WT), but MMP-9 KOs did not protect against hemorrhage. MMP-2 and/or -9 knockout mice displayed significantly decreased infarction volume in both the cortex and striatum, in addition to improved neurological function (p<0.001 vs. WT). The results suggested that MMP-2 deficiency and MMP-2 and MMP-9 double deficiency were more protective than MMP-9 deficiency against HT after the early stages of ischemia and reperfusion. These studies increase our understanding of MMP-2 and MMP-9 in HT development and will help to selectively target MMPs to protect the post-ischemic brain from injury and HT.

Conditions of tumor-associated antigens as a proper target for therapeutic antibodies against solid cancers

Since the success of rituximab and trastuzumab for treatment of non-Hodgkin’s lymphoma and breast cancer, respectively, a huge therapeutic potential of monoclonal antibodies (mAbs) was realized and development of therapeutic mAbs has been widely tried against various cancers. However, the successful examples are still limited and therapeutic mAbs are not yet available for the majority of human cancers. We established a procedure for comprehensive identification of tumor-associated antigens (TAAs) through the extensive isolation of human mAbs that may become therapeutic. Thirty-twoTAAs have been identified and 555 mAbs that bound to one of the TAAs have been isolated to date. Now we are trying to select TAAs as proper targets for therapy and candidate mAbs as drugs from among them. The immunohistochemical analysis using many fresh lung cancer specimens suggested probabilities of proper targets, and moreover, presence of cancer-specific epitopes that could be distinguished from normal epitopes on the same molecules by mAbs. For Abs to efficiently kill the cancer cells they should have the ability to induce immunological cytotoxicity such as ADCC and/or CDC. They should also be able to inhibit the function mediated by the target Ags. For clinical point of view, the continuous presence of the target molecule on the cell surface until cell death might be essential for successful treatment. Therefore, it will be required for targets TAAs to play essential roles in tumorigenesis. Otherwise the cancer cells that do not express them could selectively survive during treatment and finally become dominant. It was also suggested that even the same molecules could play different roles in tumorigenesis quite often in different patients. Therefore when we develop therapeutic Abs, we should obtain information about the conditions of patients including genetic background to whom the treatment will be effective. I will discuss how we can accomplish this purpose.

Qualitative PCR method for Roundup Ready soybean: interlaboratory study

Quantitative and qualitative methods based on PCR have been developed for genetically modified organisms (GMO). Interlaboratory studies were previously conducted for GMO quantitative methods; in this study, an interlaboratory study was conducted for a qualitative method for a GM soybean, Roundup Ready soy (RR soy), with primer pairs designed for the quantitative method of RR soy studied previously. Fourteen laboratories in Japan participated. Each participant extracted DNA from 1.0 g each of the soy samples containing 0, 0.05, and 0.10% of RR soy, and performed PCR with primer pairs for an internal control gene (Le1) and RR soy followed by agarose gel electrophoresis. The PCR product amplified in this PCR system for Le1 was detected from all samples. The sensitivity, specificity, and false-negative and false-positive rates of the method were obtained from the results of RR soy detection. False-negative rates at the level of 0.05 and 0.10% of the RR soy samples were 6.0 and 2.3%, respectively, revealing that the LOD of the method was somewhat below 0.10%. The current study demonstrated that the qualitative method would be practical for monitoring the labeling system of GM soy in kernel lots.

Basic study of brain injury mechanism caused by cavitation

The purpose of this study is to discuss the mechanism of brain injury experimentally, with respect to the pressure changes on the surface of a brain agar phantom by cavitation. First, an experimental system to perform an impact experiment is presented. We present some images taken by a high-speed camera of the behavior of a simple physical head model with and without the brain agar phantom during impact. From the photographs of the high-speed camera, we can confirm that cavitation bubbles occur at the contrecoup side, irrespective of the usage of the brain agar phantom. Second, two experimental systems to perform impact and strike experiments are presented. The pressure changes on the surface of the brain agar phantom at contrecoup side were measured by two kinds of experiments and impact velocities. Frequency analysis of the measured pressure changes was conducted by FFT software. From these results, we found that the collapse of cavitation bubbles at the contrecoup side can strongly affect the characteristics of pressure changes on the surface of the brain agar phantom.

Tendency for interlaboratory precision in the GMO analysis method based on real-time PCR

The Horwitz curve estimates interlaboratory precision as a function only of concentration, and is frequently used as a method performance criterion in food analysis with chemical methods. The quantitative biochemical methods based on real-time PCR require an analogous criterion to progressively promote method validation. We analyzed the tendency of precision using a simplex real-time PCR technique in 53 collaborative studies of seven genetically modified (GM) crops. Reproducibility standard deviation (SR) and repeatability standard deviation (Sr) of the genetically modified organism (GMO) amount (%) was more or less independent of GM crops (i.e., maize, soybean, cotton, oilseed rape, potato, sugar beet, and rice) and evaluation procedure steps. Some studies evaluated whole steps consisting of DNA extraction and PCR quantitation, whereas others focused only on the PCR quantitation step by using DNA extraction solutions. Therefore, SR and Sr for GMO amount (%) are functions only of concentration similar to the Horwitz curve. We proposed S(R) = 0.1971C 0.8685 and S(r) = 0.1478C 0.8424, where C is the GMO amount (%). We also proposed a method performance index in GMO quantitative methods that is analogous to the Horwitz Ratio.

Basic study of brain injury mechanism

The purpose of this study is to discuss the mechanism of brain injury experimentally paying attention to the pressure changes on the surface of a brain agar phantom generated by a cavitation.

Low-volume muscle endurance training prevents decrease in muscle oxidative and endurance function during 21-day forearm immobilization

AIM

To examine the effects of low-volume muscle endurance training on muscle oxidative capacity, endurance and strength of the forearm muscle during 21-day forearm immobilization (IMM-21d).

METHODS

The non-dominant arm (n = 15) was immobilized for 21 days with a cast and assigned to an immobilization-only group (Imm-group; n = 7) or an immobilization with training group (Imm+Tr-group; n = 8). Training comprised dynamic handgrip exercise at 30% of pre-intervention maximal voluntary contraction (MVC) at 1 Hz until exhaustion, twice a week during the immobilization period. The duration of each exercise session was 51.7 +/- 3.4 s (mean +/- SE). Muscle oxidative capacity was evaluated by the time constant for phosphocreatine recovery (tau(off)PCr) after a submaximal handgrip exercise using (31)phosphorus-magnetic resonance spectroscopy. An endurance test was performed at 30% of pre-intervention MVC, at 1 Hz, until exhaustion.

RESULTS

tau(off)PCr was significantly prolonged in the Imm-group after 21 days (42.0 +/- 2.8 and 64.2 +/- 5.1 s, pre- and post-intervention respectively; P < 0.01) but did not change for the Imm+Tr-group (50.3 +/- 3.0 and 48.8 +/- 5.0 s, ns). Endurance decreased significantly for the Imm-group (55.1 +/- 5.1 and 44.7 +/- 4.6 s, P < 0.05) but did not change for the Imm+Tr-group (47.9 +/- 3.0 and 51.7 +/- 4.0 s, ns). MVC decreased similarly in both groups (P < 0.01).

CONCLUSIONS

Twice-weekly muscle endurance training sessions, each lasting approx. 50 s, effectively prevented a decrease in muscle oxidative capacity and endurance; however, there was no effect on MVC decline with IMM-21d.

Genetic polymorphism of erythrocyte esterase-D in pigs

The erythrocyte esterase-D (Es-D) of four European-American pig breeds, two Taiwan native pigs (Taoyuan and Short ear breeds), Philippine native pig and wild boar populations (Sus scrofa riukiuanus) in Japan was investigated by using starch gel electrophoresis. Analysis of parentage records of the pigs revealed that the phenotypic variation of erythrocyte esterase-D was controlled by two codominant alleles Es-DA and Es-DB. The allele Es-DB was mostly found in three European-American pig breeds, Landrace (0.100), Hampshire (0.135) and Duroc (0.102). All of the wild boar populations were monomorphic for allele Es-DA.

Electrophoretic variants of serum transferrin in wild pig populations of Japan

Variants of serum transferrin in Japanese wild pig, Sus scrofa leucomystax, and Ryukyu wild pig, S.s. riukiuanus, of Japan were investigated by using starch gel electrophoresis. Five phenotypes, TfB, BC, C, CX and X, were observed, of which two, TfCX and X, are new variants. Comparison of gene frequency estimates which were calculated for each population showed remarkable geographic differences among several populations of these two subspecies.

Genetic relationship among several pig populations in East Asia analysed by blood groups and serum protein polymorphisms

The gene frequencies were calculated to investigate genetic variation apparent in blood group and serum protein systems in Asian native pigs. The results revealed that gene frequencies were generally similar in the nine pig populations, except in some systems. Differences of gene frequencies were recognized in HpY and Cpc detected on Taoyuan pigs of Taiwan and Ohmini pigs of Japan, respectively. TfC and AmC alleles were found in eight pig populations except Ohmini pigs. The overall genetic distances were calculated by gene frequencies of 13 loci and it was observed that Taoyuan pigs are closer to Ohmini pigs than to Short-ear pigs of Taiwan and other East Asian native pigs. However, the genetic distances between Asian native pigs and European or American breeds were larger than those among East Asian native pig populations.

Immunogenetic studies on wild pigs in Japan

The variations of blood groups in the two subspecies of wild pigs in Japan (Sus scrofa leucomystax and S.s. riukiuanus) were investigated by serological techniques. S.s. leucomystax showed polymorphism in the A and F systems. S.s. riukiuanus showed a little polymorphism in the F system only. As a whole, there was a great similarity in erythrocyte antigen structures of both S.s. leucomystax and S.s. riukiuanus. In comparison with the erythrocyte antigen frequenties of wild pigs in the Eurasian Continent reported by other workers. East-West geographical clines in the frequencies of Ea, Fa, Ga, Ka, Kb and Lh antigens were clearly observed. From the results of investigation on genetic similarities among seven wild pig populations, it was made clear that the two Japanese strains were very close and were closer to Far Eastern TS.s. ussuricus) than Middle Asian (S.s. nigripes), Transcausian (S.s. attila) and European pigs (S.s. ferus).

PGD variants in several wild pig populations of east Asia

PGD (6-phosphogluconate dehydrogenase) gene frequencies were reported in wild pigs, Sus scrofa, of three subspecies, i.e. Japanese wild pig, S.s. leucomystax, Ryukyu wild pig, S.s. riukiuanus, and Formosan wild pig, S.s. taivanus. Five phenotypes (A, AB, B, AC' and C') were observed. The C' variant was found only in the S.s. leucomystax, and may be identical to PGD-C reported by Archibald & McTeir (1988). PGD-A was a common variant in all the species in the genus Sus including wild pig, Sus scrofa, Javan pig, Sus verrucosus, and Bearded pig, Sus barbatus, and predominated in the whole populations examined except some of those of the S.s. riukiuanus. This suggested that the PGDA appeared before the other two alleles (B and C') during the evolution of the genus Sus.

3-D finite element analysis on brain injury mechanism

The purpose of this study is to discuss the mechanism of brain injury analytically by a cavitation phenomenon. Cavitation damage is assumed to be one of the causes brain injury. Performing the computer simulation of brain injury, it is not easy to incorporate the term of a cavitation occurrence in a governing equation. Therefore, we predict the cavitation occurrence from the results of stress, pressure, and displacement of the analytical model by FEM. Here, comparing frequency and pressure changes, we discussed the basic mechanism of brain injury analytically. First, a three-dimensional FEM model for impact analysis was presented. The high-pressure changes generated in the acrylic container at the time of impact were transmitted through this container, and the positive maximum pressure change was caused at the contrecoup side. Second, the results of the frequency analysis of pressure changes by a FFT were presented. We found spectrums in some frequency bands, which seemed to be the occurrence of the brain injury. From these results, it was found that the computer simulation methods were useful to predict the occurrence mechanism of contrecoup injury.

Toward metrological traceability for DNA fragment ratios in GM quantification. 1. Effect of DNA extraction methods on the quantitative determination of Bt176 corn by real-time PCR

An international CCQM-P60 pilot study involving eight national metrological institutes was organized to investigate if the quantification of genetically modified (GM) corn powder by real-time PCR was affected by the DNA extraction method applied. Four commonly used extraction methods were compared for the extraction of DNA from a GM Bt176 corn powder. The CTAB-based method yielded the highest DNA template quantity and quality. A difference in the 260 nm/230 nm absorbance ratio was observed among the different extraction methods. Real-time amplification of sequences specific for endogenous genes zein and hmg as well as transgenic sequences within the cryIA(b) gene and a fragment covering the junction between the transformed DNA and the plant genome were used to determine the GM percentage. The detection of the transgenic gene was affected by the quantity and quality of template used for the PCR reaction. The Bt176 percentages measured on diluted or purified templates were statistically different depending on the extraction method applied.

Circumventing air bubbles in microfluidic systems and quantitative continuous-flow PCR applications

Polymerase chain reaction (PCR) is an essential part of research based on genomics or cell analysis. The development of a microfluidic device that would be suitable for high-temperature-based reactions therefore becomes an important contribution towards the integration of micro-total analysis systems (muTAS). However, problems associated with the generation of air bubbles in the microchannels before the introduction of the assay liquid, which we call the "initial start-up" in this study, made the flow irregular and unstable. In this report, we have tried to address these problems by adapting a novel liquid-flow method for high-temperature-based reactions. A PDMS-based microfluidic device was fabricated by soft-lithography techniques and placed on a cartridge heater. The generation of the air bubbles was prevented by introducing the fluorinated oil, an inert and highly viscous liquid, as the cap just before the introduction of the sample solutions into the microchannels. The technique was applied for continuous-flow PCR, which could perform PCR on-chip in a microfluidic system. For the evaluation of practical accuracy, plasmid DNA that serves as a reference molecule for the quantification of genetically modified (GM) maize was used as the template DNA for continuous-flow PCR. After PCR, the products were collected in a vial and analyzed by gel electrophoresis to confirm the accuracy of the results. Additionally, quantitative continuous-flow PCR was performed using TaqMan technology on our PCR device. A laser detection system was also used for the quantitative PCR method. We observed a linear relationship between the threshold cycle (Ct) and the initial DNA concentration. These results showed that it would be possible to quantify the initial copies of the template DNA on our microfluidic device. Accurate quantitative DNA analysis in microfluidic systems is required for the integration of PCR with muTAS, thus we anticipate that our device would have promising potential for applications in a wide range of research.

Novel Method to Examine Hepatocyte-Specific Gene Expression in a Functional Coculture System

To mimic native tissue function, coculture systems are an extremely useful model. In many cases, differentiated functions can be maintained only through the interactions of various cell types. Therefore, methods for examining the interactions between cocultured cells are necessary. The assessment of cell-to-cell cross-talk at the level of gene expression is one such method to examine interactions between different cell types. However, it is generally difficult to determine the gene expression of specific cell types in coculture without first separating cell populations. To overcome these obstacles, we have established a novel method to determine gene expression levels of a targeted cell population in coculture, using species-specific primers. With this approach, we were able to determine hepatocyte-specific gene expression of Fao cells (a rat hepatocyte cell line) in culture with human umbilical vein endothelial cells (HUVECs). Expression of both albumin and apolipoprotein A-I (apoA-I) increased time dependently for 10 days and maintained significantly higher expression in the coculture system as compared with isolated Fao cells. This indicates that hepatocyte function increased gradually in our coculture system and could be maintained long-term, suggesting that the construction of mature cell-to-cell communication between the two cell lines required a considerable amount of time. The expression of HNF-4 and HNF-1alpha, which are liver-enriched transcription factors, did not differ between the monolayer and cocultured Fao cells, suggesting that expression of HNF-4 and HNF-1alpha was not responsible for the increased expression albumin and apoA-I. Our findings suggest that this novel method for the detection of gene expression of targeted cell populations can be a useful tool in determining the molecular mechanisms that regulate communication between different cell types.

Serodiagnosis of Japanese encephalitis among Nepalese patients by the particle agglutination assay

Japanese encephalitis (JE) is a serious health problem in the southwestern region of Nepal. Serological diagnostic kits for routine diagnostic use in this region have not been available. This study was performed to examine if the particle agglutination (PA) assay for Japanese encephalitis virus (JEV) IgM could be applicable to the samples collected in Nepal and also to evaluate the accuracy of clinical diagnosis of JE. One hundred and ninety-three blood samples were collected from the patients clinically diagnosed with JE or other infectious diseases in the JE-endemic, southwestern region of Nepal, in 2000. The PA assay was performed on these 193 serum samples and the results were compared with those by IgM-capture ELISA. Eighty-six samples were IgM-positive by the PA assay, and 71 of 86 were also positive by IgM-capture ELISA (sensitivity, 99%; specificity, 88%; positive predictive value, 0.82; negative predictive value, 0.99). These results suggest that the PA assay is a simple, reliable and useful diagnostic test to support clinical diagnosis in rural hospitals of Asia including Nepal.

Expression of foreign proteins in Escherichia coli by fusing with an archaeal FK506 binding protein

Improper protein-folding often results in inclusion-body formation in a protein expression system using Escherichia coli. To express such proteins in the soluble fraction of E. coli cytoplasm, we developed an expression system by fusing the target protein with an archaeal FK506 binding protein (FKBP). It has been reported that an archaeal FKBP from a hyperthermophilic archaeon, Thermococcus sp. KS-1 (TcFKBP18), possesses not only peptidyl-prolyl cis-trans isomerase activity, but also chaperone-like activity to enhance the refolding yield of an unfolded protein by suppressing irreversible protein aggregation. To study the effect of this fusion strategy with FKBP on the expression of foreign protein in E. coli, a putative rhodanese (thiosulfate sulfurtransferase) from a hyperthermophilic archaeon and two mouse antibody fragments were used as model target proteins. When they were expressed alone in E. coli, they formed insoluble aggregates. Their genes were designed to be expressed as a fusion protein by connecting them to the C-terminal end of TcFKBP18 with an oligopeptide containing a thrombin cleavage site. By fusing TcFKBP18, the expression of the target protein in the soluble fraction was significantly increased. The percentage of the soluble form in the expressed protein reached 10-28% of the host soluble proteins. After purification and protease digestion of the expressed antibody fragment-TcFKBP18 fusion protein, the cleaved antibody fragment (single-chain Fv) showed specific binding to the antigen in ELISA. This indicated that the expressed antibody fragment properly folded to the active form.

UDP-glucuronic acid:soyasapogenol glucuronosyltransferase involved in saponin biosynthesis in germinating soybean seeds

We detected UDP-glucuronic acid:soyasapogenol glucuronosyltransferase (UGASGT) activity in the microsomal fraction from germinating soybean (Glycine max [L.] Merr.) seed. A microsomal fraction was isolated from germinating soybean seed and treated with various detergents to solubilize the enzyme. UGASGT activity was monitored throughout purification using UDP-[U-(14)C]glucuronic acid and soyasapogenol B as substrates. Purification of UGASGT was achieved by HiTrap Q, Superdex 200, and HiTrap Blue chromatography procedures. This resulted in >205-fold enrichment relative to the starting homogenate. UGASGT was found to require divalent cations for activity. Studies on the substrate specificity of UGASGT demonstrated that the specificity for the sugar residue transferred was very high, as activity was scarcely found when UDP-glucuronic acid was replaced by other UDP sugars: UDP-glucose and UDP-galactose. Soyasapogenols, which are the aglycons of soybean saponin, are usable acceptors, but glycyrrhetinic acid, sophoradiol, beta-amyrin, and flavonoids are not. These findings suggest that this UGASGT was a specific enzyme for UDP-glucuronic acid as a donor and soyasapogenols as acceptors, and that it was related to the biosynthesis of the sugar chain in soybean saponin. This study provides a basis for the molecular characterization of a key enzyme in saponin biosynthesis in soybean. The isolation of the gene may enable its use in the elucidation of the biosynthesis and physiological role of saponins in soybean.

Antibody fusions with fluorescent proteins: a versatile reagent for profiling protein expression

We developed a system by which antibodies, fused to fluorescent proteins with different wavelengths, can be prepared within a month against various antigens. An antibody library composed of a large number of single-chain Fv-CL fragment was constructed by means of a phage-display system. The constructs were designed to facilitate changing of the protein forms by simple enzyme manipulation. In the present study, we adopted a molecular form of antibody in which a single-chain Fv-CL fragment is fused with a green fluorescent protein (GFP) or red fluorescent protein (RFP). In addition, a His-tag was inserted between CL and GFP (or RFP). We describe the utility of this system using Caenorhabditis elegans embryo as a model.

[Study on the effects of walking on functional fitness in aged patients with the hand-arm vibration syndrome]

PURPOSE

This article reports the effectiveness of mild walking exercise for maintaining functional fitness in aged patients with the hand-arm vibration syndrome (HAVS).

SUBJECTS AND METHODS

Fifty-two patients suffering from vibration syndrome, for which they received annual compulsory examination from December 1998 to March 1999 at the San-in Rosai Hospital, were examined. They all were male, with a mean age (standard deviation) of 69.1 (7.3) years, and were randomly allocated to an intervention group (N = 26) and a control group (N = 26). The goal of the intervention was to achieve and maintain at least 30 minutes of walking a day. Functional fitness was assessed by a sitting and standing test, a zigzag walking test, a hand working test with a pegboard for dexterity, and a self-care working test proposed by the Physical Fitness Research Institute, Meiji Life Foundation of Health and Welfare.

RESULTS

There were no significant differences between the two groups regarding baseline characteristics. The proportions of subjects with regular exercise habits after the intervention were 84.6% (22/26) and 53.8% (14/26) in the intervention and control groups, respectively, the difference being significant. The total scores for functional fitness were improved in the intervention, while decline was noted in the control group. Sitting and standing and self-care working ability were also improved in the intervention group as against the deterioration with age in the control group.

CONCLUSIONS

Our findings show to some extent that intervention using mild exercise, walking for 30 min, is effective for aged patients with HAVS to maintain and improve functional fitness.

Age-dependent and tissue-specific CAG repeat instability occurs in mouse knock-in for a mutant Huntington's disease gene

Huntington's disease (HD) is a neurodegenerative disorder characterized by the expansion of CAG repeats in exon 1 of the HD gene. To clarify the instability of expanded CAG repeats in HD patients, an HD model mouse has been generated by gene replacement with human exon 1 of the HD gene with expansion to 77 CAG repeats. Chimeric proteins composed of human mutated exon 1 and mouse huntingtin are expressed ubiquitously in brain and peripheral tissues. One or two CAG repeat expansion was found in litters from paternal transmission, whereas contraction of CAG repeat in litters was observed through maternal transmission. Elderly mice show greater CAG repeat instability than younger mice, and a unique case was observed of an expanded 97 CAG repeat mouse. Somatic CAG repeat instability is particularly pronounced in the liver, kidney, stomach, and brain but not in the cerebellum of 100-week-old mice. The same results of expanded CAG repeat instability as observed in this HD model mouse were confirmed in the human brain of HD patients. Glial fibrillary acidic protein (GFAP)-positive cells have been found to be increased in the substantia nigra (SN), globus pallidus (GP), and striatum (St) in the brains of 40-week-old affected mice, although without neuronal cell death. The CAG repeat instability and increase in GFAP-positive cells in this mouse model appear to mirror the abnormalities in HD patients. The HD model mouse may therefore have advantages for investigations of molecular mechanisms underlying instability of CAG repeats.

Fluvastatin inhibits O2- and ICAM-1 levels in a rat model with aortic remodeling induced by pressure overload

Upregulation of intercellular adhesion molecule-1 (ICAM-1) expression is suggested to play an important role in the pathogenesis of vascular remodeling. The aim of the present study was to investigate the effects of the 3-hydroxy-3-methylglutaryl (HMG) CoA reductase inhibitor fluvastatin on superoxide anion (O2-) production and ICAM-1 expression in a rat model with vascular remodeling induced by pressure overload. Two weeks after aortic banding, marked increases in O2- production and ICAM-1 protein levels were observed in the aorta. O2- formation and ICAM-1 immunoreactivity were mainly increased in the endothelium and adventitia of the aorta in banded rats. Oral administration of fluvastatin prevented both these changes and the development of perivascular fibrosis and increased the expression of endothelial nitric oxide synthase. Cholesterol and lipid peroxide levels in serum did not change in the banded rats. Thus the beneficial effects of fluvastatin seen in this study as well as its cholesterol-lowering effect may contribute to attenuate the atherosclerotic process.