Serum anti-DIDO1, anti-CPSF2, and anti-FOXJ2 antibodies as predictive risk markers for acute ischemic stroke.

BACKGROUND: Acute ischemic stroke (AIS) is a serious cause of mortality and disability. AIS is a serious cause of mortality and disability. Early diagnosis of atherosclerosis, which is the major cause of AIS, allows therapeutic intervention before the onset, leading to prevention of AIS. METHODS: Serological identification by cDNA expression cDNA libraries and the protein array method were used for the screening of antigens recognized by serum IgG antibodies in patients with atherosclerosis. Recombinant proteins or synthetic peptides derived from candidate antigens were used as antigens to compare serum IgG levels between healthy donors (HDs) and patients with atherosclerosis-related disease using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay. RESULTS: The first screening using the protein array method identified death-inducer obliterator 1 (DIDO1), forkhead box J2 (FOXJ2), and cleavage and polyadenylation specificity factor (CPSF2) as the target antigens of serum IgG antibodies in patients with AIS. Then, we prepared various antigens including glutathione S-transferase-fused DIDO1 protein as well as peptides of the amino acids 297-311 of DIDO1, 426-440 of FOXJ2, and 607-621 of CPSF2 to examine serum antibody levels. Compared with HDs, a significant increase in antibody levels of the DIDO1 protein and peptide in patients with AIS, transient ischemic attack (TIA), and chronic kidney disease (CKD) but not in those with acute myocardial infarction and diabetes mellitus (DM). Serum anti-FOXJ2 antibody levels were elevated in most patients with atherosclerosis-related diseases, whereas serum anti-CPSF2 antibody levels were associated with AIS, TIA, and DM. Receiver operating characteristic curves showed that serum DIDO1 antibody levels were highly associated with CKD, and correlation analysis revealed that serum anti-FOXJ2 antibody levels were associated with hypertension. A prospective case-control study on ischemic stroke verified that the serum antibody levels of the DIDO1 protein and DIDO1, FOXJ2, and CPSF2 peptides showed significantly higher odds ratios with a risk of AIS in patients with the highest quartile than in those with the lowest quartile, indicating that these antibody markers are useful as risk factors for AIS. CONCLUSIONS: Serum antibody levels of DIDO1, FOXJ2, and CPSF2 are useful in predicting the onset of atherosclerosis-related AIS caused by kidney failure, hypertension, and DM, respectively.

Association of serum levels of antibodies against ALDOA and FH4 with transient ischemic attack and cerebral infarction.

BACKGROUND: Ischemic stroke, including transient ischemic attack (TIA) and acute-phase cerebral infarction (aCI), is a serious health problem in the aging society. Thus, this study aimed to identify TIA and aCI biomarkers. METHODS: In 19 patients with TIA, candidate antigens recognized by serum IgG autoantibodies were screened using a human aortic endothelial cell cDNA library. Through amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA), serum antibody levels against the candidate antigens were examined in healthy donor (HD), TIA, and aCI cohorts (n = 285, 92, and 529). The plasma antibody levels in the Japan Public Health Center-based Prospective Cohort Study (1991-1993) were also examined. RESULTS: The candidate antigens were aldolase A (ALDOA) and fumarate hydratase (FH). In AlphaLISA, patients with TIA or aCI had higher anti-ALDOA antibody (ALDOA-Ab) and anti-FH antibody (FH-Ab) levels than the HDs (P < 0.05). In a multivariate logistic regression analysis, the ALDOA-Ab (odds ratio [OR]: 2.46, P = 0.0050) and FH-Ab (OR: 2.49, P = 0.0037) levels were independent predictors of TIA. According to the case-control study, the ALDOA-Ab (OR: 2.50, P < 0.01) and FH-Ab (OR: 2.60, P < 0.01) levels were associated with aCI risk. In a correlation analysis, both ALDOA-Abs and FH-Abs were well associated with hypertension, coronary heart disease, and habitual smoking. These antibody levels also correlated well with maximum intima-media thickness, which reflects atherosclerotic stenosis. CONCLUSIONS: ALDOA-Abs and FH-Abs can be novel potential biomarkers for predicting atherosclerotic TIA and aCI.

Serum anti-LRPAP1 is a common biomarker for digestive organ cancers and atherosclerotic diseases.

Some cancers are related to atherosclerotic diseases; therefore, these two types of disease may share some antibody biomarkers in common. To investigate this, a first screening of sera was performed from patients with esophageal squamous cell carcinoma (ESCC) or acute ischemic stroke (AIS) for serological identification of antigens using recombinant cDNA expression cloning (SEREX). The amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) method, which incorporates glutathione donor beads and anti-human IgG acceptor beads, was used to evaluate serum antibody levels. SEREX screening identified low-density lipoprotein receptor-related protein-associated protein 1 (LRPAP1) as a target antigen of serum IgG antibodies in the sera of patients with ESCC or AIS. Antigens, including recombinant glutathione S-transferase-fused LRPAP1 protein, were prepared to examine serum antibody levels. AlphaLISA revealed significantly higher antibody levels against the LRPAP1 protein in patients with solid cancers such as ESCC and colorectal carcinoma and some atherosclerosis-related diseases such as AIS and diabetes mellitus compared with healthy donors. Correlation analysis revealed that the elevated serum antibody levels against LRPAP1 were associated with smoking, a well-known risk factor for both cancer and atherosclerosis. Serum LRPAP1 antibody is therefore a common marker for the early diagnosis of some cancers and atherosclerotic diseases and may reflect diseases caused by habitual smoking.

Serum alkaline phosphatase isoenzymes in SD rats detected by polyacrylamide-gel disk electrophoresis.

Serum alkaline phosphatase (ALP) activity is frequently measured in toxicity studies. In the present study, we assessed the usefulness of a commercially available polyacrylamide-gel disk electrophoresis kit used in humans (AlkPhor System, Jokoh Co. Ltd., Tokyo, Japan) for identifying serum ALP isoenzymes in rats of the Sprague-Dawley strain (SD rats), which are commonly used in toxicity studies. We also examined age-related changes in serum ALP isoenzymes in SD rats. In order to identify the origin of each ALP isoenzyme, tissue ALP extracts from the liver, bone and small intestine (SI) and serum samples were treated with neuraminidase, antiintestinal ALP antibody, ALP inhibitor levamisole, and/or wheat germ agglutinin. It became clear that pretreatment of serum with neuraminidase is necessary for rat serum ALP isoenzyme analysis. The kit revealed that the main serum ALP isoenzymes in fasted 8-week-old intact rats were bone- and SI-derived and they tended to decrease with age. Serum liver-derived isoenzyme was slightly detected in both sexes of all ages examined, but it greatly increased in cholestasis model rats with bile-duct ligation, and rats of this model also had large molecular ALP detected in the stacking gel, suggesting hepatic damage. High-molecular intestinal ALP isoenzyme was slightly observed at the most cathodal side of the resolving gel. These results suggest that the present method is a useful tool for detecting serum ALP isoenzymes in SD rats and that concomitant levamisole inhibition with another gel is applicable for the evaluation of organ toxicity.

TGF-{beta} maintains dormancy of prostatic stem cells in the proximal region of ducts.

We have previously shown that prostatic stem cells are located in the proximal region of mouse prostatic ducts. Here, we show that this region responds differently to transforming growth factor (TGF)-beta than the distal ductal region and that under physiological conditions androgens and TGF-beta are crucial overall regulators of prostatic tissue homeostasis. This conclusion is supported by the observations showing that high levels of TGF-beta signaling are present in the quiescent proximal region of ducts in an androgen-replete animal and that cells in this region overexpress Bcl-2, which protects them from apoptosis. Moreover, androgen ablation reverses the proximal-distal TGF-beta signaling gradient, leading to an increase in TGF-beta signaling in the unprotected distal region (low Bcl-2 expression). This reversal of TGF-beta-mediated signaling accompanies apoptosis of cells in the distal region and gland involution after androgen withdrawal. A physiological TGF-beta signaling gradient (high proximally and low distally) and its functional correlates are restored after androgen replenishment. In addition to highlighting the regulatory role of androgens and TGF-beta, these findings may have important implications for the deregulation of the stem cell compartment in the etiology of proliferative prostatic diseases.

Scoring evaluation for histopathological features of synovium in patients with rheumatoid arthritis during anti-tumor necrosis factor therapy.

The present study was performed to evaluate the synovium in patients with rheumatoid arthritis (RA) treated with anti-tumor necrosis factor alpha agents (anti-TNFalpha). Synovial tissue specimens were obtained during total knee arthroplasty (TKA) from 42 RA patients (12 men, 30 women). Twenty-one RA patients were given anti-TNFalpha agents (infliximab, n = 12; etanercept, n = 9), while the remaining 21 RA patients were given no such agents.The histopathological findings were compared between specimens from these groups using the histological scoring system reported by Rooney, which consists of six items:degree of synovial hyperplasia, fibrosis, number of blood vessels, perivascular lymphocyte infiltration, focal aggregates of lymphocytes, and diffuse infiltrates of lymphocytes.Clinical laboratory data including C-reactive protein(CRP), matrix metalloproteinase-3 (MMP-3), and disease activity scores including a 28-joint count (DAS28), disease duration, methotrexate (MTX) dose, and glucocorticoid dose were also assessed before surgery. There were no significant differences in total score between anti-TNFalpha and no anti-TNFalpha groups. However, significant differences were observed in scores of synoviocyte hyperplasia and perivascular infiltrates of lymphocytes between the groups. These results suggested that these agents have a suppressive effect on cell proliferation in the lining layer and on perivascular lymphocyte infiltration. However, further studies are necessary to elucidate the mechanisms of these effects.

Molecular basis for affected cartilage formation and bone union in fracture healing of the streptozotocin-induced diabetic rat.

Most studies have focused on the association between diabetes mellitus (DM) and impaired osseous healing, but there is also evidence that diabetes impairs cartilage formation during fracture healing. To investigate the molecular mechanisms by which diabetes affects endochondral ossification, experiments were performed in a model of rat closed fracture healing complicated with diabetes. Diabetic rats were created by a single intravenous injection of streptozotocin (STZ), while controls were treated with vehicle alone. Fractures were made 2 weeks after STZ injection. Animals were killed at 4, 7, 10, 14, 21, 28 and 42 days following fracture, and samples were subject to radiographic, histological and molecular analyses. In the DM group, a significantly smaller cartilaginous callus was formed compared with controls throughout healing, with the cartilage area being reduced rapidly after day 14. When the bone union rate was evaluated radiographically on day 28, DM calluses exhibited a lower rate than controls. However, when evaluated on day 42, both groups showed an equivalent union rate. Cellular proliferation of chondroprogenitor cells and proliferating chondrocytes in soft calluses of the DM group was significantly reduced during early stages of healing (days 4 and 7), but no longer reduced thereafter. Moreover, expression levels of collagen type II, type X and osteopontin (OPN) were constantly low in the DM group. These results show the molecular basis for diminished cartilage formation and delayed union in fracture healing of the STZ-induced diabetic rats.

Validation of Partin tables and development of a preoperative nomogram for Japanese patients with clinically localized prostate cancer using 2005 International Society of Urological Pathology consensus on Gleason grading: data from the Clinicopathological Research Group for Localized Prostate Cancer.

PURPOSE: We validated the 2001 Partin tables and developed an original nomogram for Japanese patients using the 2005 International Society of Urological Pathology consensus on Gleason grading. MATERIALS AND METHODS: Prostatectomy specimens from 1,188 Japanese men who underwent radical prostatectomy for clinically localized prostate cancer (cT1-2) between 1997 and 2005 were analyzed. Polychotomous logistic regression analysis was used to construct a nomogram to predict final pathological stage (organ confined disease, extraprostatic extension, seminal vesicle invasion and lymph node involvement) from 3 variables, including serum prostate specific antigen, clinical stage and biopsy Gleason score. The area under the ROC curve was used to compare the new nomogram with the Partin tables. RESULTS: Preoperative serum prostate specific antigen and biopsy Gleason score were higher in the Japanese cohort than in the Partin cohort. The distribution of clinical and final pathological stages was similar in the 2 cohorts. The AUC for predicting organ confined disease was 0.699 and 0.717 for data applied to the Partin tables and to the new nomogram, respectively. The AUC for predicting lymph node involvement was 0.793 and 0.863, respectively. CONCLUSIONS: To our knowledge this is the first preoperative nomogram developed for clinically localized prostate cancer in Japanese patients. Although the new nomogram predicted the pathological stage of prostate cancer in Japanese patients more accurately than the Partin tables, it did not satisfactorily predict organ confined disease. However, other predictive variables, such as more detailed pathological features of biopsy specimens or magnetic resonance imaging, may further improve prediction accuracy.

Association of serum levels of antibodies against MMP1, CBX1, and CBX5 with transient ischemic attack and cerebral infarction.

Transient ischemic attack (TIA) is a predictor for cerebral infarction (CI), and early diagnosis of TIA is extremely important for the prevention of CI. We set out to identify novel antibody biomarkers for TIA and CI, and detected matrix metalloproteinase 1 (MMP1), chromobox homolog 1 (CBX1), and chromobox homolog 5 (CBX5) as candidate antigens using serological identification of antigens by recombinant cDNA expression cloning (SEREX) and Western blotting to confirm the presence of serum antibodies against the antigens. Amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA) revealed that serum antibody levels were significantly higher in patients with TIA or acute-phase CI (aCI) compared with healthy donors (P < 0.01). Spearman's correlation analysis and multivariate logistic regression analysis demonstrated that levels of anti-MMP1, anti-CBX1, and anti-CBX5 antibodies were associated with age, cigarette-smoking habits, and blood pressure. Thus, serum levels of antibodies against MMP1, CBX1, and CBX5 could potentially serve as useful tools for diagnosing TIA and predicting the onset of aCI.

Sensitization against anticancer drugs by transfection with UBE2I variant gene into ras-NIH3H3 mouse fibroblasts.

We previously performed SEREX (serological identification of antigens by recombinant expression cloning) using the sera of patients with esophageal squamous cell carcinoma (SCC), and isolated a variant clone (AK093616) of ubiquitin-conjugating enzyme E21 (UBE2I). This clone was tentatively designated as UBE2I-v5 and analyzed for biological function by transient transfection of the cDNA into activated Ha-ras-transformed NIH3T3 (ras-NIH) mouse fibroblasts. Chemosensitivity to 92 cytotoxic drugs was compared between UBE2I-v5-transfected cells and the parental ras-NIH cells. The UBE2I-v5-transfected cells were more sensitive than the parental cells to anticancer drugs such as vincristine (VCR), mitoxantrone (MIT) and etoposide (VP16). The regression analysis of the total chemosensitivity pattern of UBE2I-vS-transfected cells revealed that the function of UBE2I-v5 was positively related to RPA2 (replication protein A2), Rho-GDI (Rho guanine nucleotide dissociation inhibitor a), FUS (putative tumor suppressor) and TKT (transketolase) but negatively related to Per-1 (period-I), Ran (nuclear Ras-related protein), PTEN (phosphatase and tensin homolog), C/EBPalpha (CCAAT/enhancer binding protein a) and the tumor suppressor p53. Thus, it is possible that UBE21-v5 plays a role in carcinogenesis by suppressing the function of CIEBPa and/or p53 via RPA2-like activity.

Phytochrome-like responses in Euglena: A low fluence response that reorganizes the spectral dependence of the high irradiance response in long-day photoperiodic induction of cell division.

Irradiance spectra change spatiotemporally, and angiosperms adapt accordingly, mainly through phytochromes. This study challenges the long-held belief that the flagellated alga Euglena gracilis lacks phytochromes and is therefore unaffected by spectral changes. We photoautotrophically cultured the alga under continuous light (LL), then transferred it to darkness. After about 26h in darkness, different irradiations for 3h enabled cell division in dark-arrested G2 cells evoking a high-irradiance response (HIR). The spectral characteristics of the irradiation during the LL period (pre-irradiation) defined the spectral sensitivity in the subsequent dark period. LL with light rich in the red spectrum led to a HIR to the red spectrum (R-HIR), whereas light rich in the far-red spectrum (FR) led to a FR-HIR. Finishing the period of pre-irradiation consisting of continuous cool-white fluorescent light (rich in R) by a FR pulse enhanced the characteristics of the FR-HIR 26h later. By contrast, a R pulse given at the end of the pre-irradiation rich in FR potentiated the R-HIR. The effects were completely photoreversible between R and FR with critical fluences of about 2mmolm(-2), satisfying the classic diagnostic feature of phytochromes. The action spectrum of the FR effect at the end of pre-irradiation consisting of continuous cool-white fluorescent light (rich in R) had a main peak at 740nm and a minor peak at 380nm, whereas antagonization of the FR effect had a main peak at 640nm and a minor peak at 480nm. Wavelengths of 610 and 670nm appeared in both spectra. We also demonstrated the photoreversibility of 380/640, 480/740, and (610 and 670)/(640 and 740) nm. We conclude that Euglena displays phytochrome-like responses similar to the 'shade avoidance' and 'end-of-day FR' effects reported in angiosperms.

High irradiance responses involving photoreversible multiple photoreceptors as related to photoperiodic induction of cell division in Euglena.

Little is known about the photoreceptors involved in the photoperiodism of unicellular organisms, which we elucidated by deriving their action spectra. The flagellated alga Euglena gracilis exhibits photoperiodism, with a long-day response in cell reproduction. The underlying clock is a circadian rhythm with photoinductive capability, peaking at subjective dusk and occurring at the 26th hour in continuous darkness (DD) when transferred from continuous light (LL); it regulates photoinduction, a high-irradiance response (HIR), of a dark-capability of progressing through cell division. We derived the action spectra by irradiating E. gracilis with monochromatic light for 3h at around the 26th hour; the action maxima occurred at 380, 450-460, 480, 610, 640, 660, 680, and 740nm. Except for the maximum at 450-460nm, which was always a major maximum, the maxima greatly depended on the red (R)/far-red (FR) ratio of the prior LL. The high R/FR ratio resulted in a dominant major peak at 640nm and minor peaks at 480 and 680nm, whereas the low ratio resulted in dominant major peaks at 610 and 740nm and minor peaks at 380 and 660nm; the critical fluence was minimally about 60mmolm(-2). These HIRs resulted from the accumulation of corresponding low-fluence responses (LFRs) because we found that repetition of a 3-min light/dark cycle, with critical fluences of 1mmolm(-2), lasting for 3h resulted in the same photoinduction as the continuous 3-h irradiation. Moreover, these LFRs expressed photoreversibility. Thus, photoperiodic photoinduction involves Euglena-phytochrome (640 and 740nm) and blue photoreceptor (460nm). Although 380, 480, 610, 660, and 680nm may also represent Euglena-phytochrome, a definite conclusion awaits further study.

Background data on NOD/Shi-scid IL-2Rγnull mice (NOG mice).

To obtain background data of NOD/Shi-scid IL-2Rγnull (NOG) mice, severely immunedeficient mice, a total of 120 animals were examined at 7, 26 and 52 weeks-old (20 mice/sex/group). The survival rate at 52 weeks-old was 95% (19/20) in both sexes. Clinically, circling behavior in one direction along the cage wall was observed in males after 8 weeks and females after 47 weeks-old, and hunchback position was found in males after 32 weeks-old. Hematologically, lymphocyte count markedly decreased at all ages, while white blood cell count increased in several mice at 52 weeks-old. Blood chemistry results revealed high values of aspartate aminotransferase, lactate dehydrogenase and creatine phosphokinase in some females at 26 weeks-old, without any related histological change. Histologically, lymphoid hypoplasia characterized by severe lymphocyte depletion with poorly developed tissue architectures was observed. In addition, spongiotic change in the nerve tissue was observed in both sexes at 7 and 26 weeks-old, and intracytoplasmic materials known as tubular aggregates in the skeletal muscles were found in males terminated at 26 and 52 weeks-old and in females at 52 weeks-old. Malignant lymphoma was found in one female euthanized at 20 weeks-old. Further, small intestinal adenoma, hepatocellular adenoma, leukemia, cerebral lipomatous hamartoma, Harderian gland adenoma and uterine polyp were also observed, and their incidences were low except for that of uterine polyp. This study provided detailed background data on NOG mice up to 52 weeks-old and provided information on appropriate use of NOG mice in the various research fields.

Circadian rhythms of the L-ascorbic acid level in Euglena and spinach.

Plant defenses against photo-oxidative stress have been studied almost exclusively with respect to stress responses, and little is known about how non-enzymic antioxidants change under constant conditions without a time cue or an environmental stress. Here, we show that, in both the flagellated alga Euglena gracilis Z and the angiosperm Spinacia oleracea L., the potent antioxidant L-ascorbic acid (Asc) displays a circadian rhythm with a maximum at subjective midday, a physiological state reflecting that attained at noon under daily light/dark cycles. Thus, photosynthetic organisms can maximize antioxidant levels in anticipation of midday, when photo-oxidative stress is most severe. These results may partly explain the in-phase circadian UV-C resistance rhythm recently identified in the alga. However, the Asc, but not the resistance, rhythm wanes in continuous darkness. This suggests the presence of persistent circadian rhythms in the levels of other antioxidants in continuous darkness, which may account for the UV-C resistance rhythm.

Evaluation of a single-dose PIGRET assay for acetaminophen in rats compared with the RBC Pig-a assay.

As a part of a collaborative study of the Pig-a assay by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagen Society, a genotoxicity study on acetaminophen (APAP) was performed using the red blood cell (RBC) Pig-a and PIGRET assays. The dose levels were set at 0 (vehicle, 0.5% methylcellulose solution), 500, 1000, and 2000mg/kg, and APAP was administered once by oral gavage to male Sprague Dawley rats. For the positive control group, N-nitroso-N-ethylurea (ENU, 40mg/kg) was administered in the same way. The RBC Pig-a and PIGRET assays were performed using peripheral blood collected at pre-dosing and 1, 2 and 4 weeks after dosing. In both the RBC Pig-a and PIGRET assays, there were no changes in the Pig-a gene mutant frequency (MF) by the APAP treatment at any time point. The Pig-a MFs as measured by the RBC Pig-a assay for the ENU-treated group increased in a time-dependent manner with the maximum value at week 4; however, those using the PIGRET assay reached comparable values at week 1. Based on the above results, APAP was determined to have no mutagenicity under the conditions of this study, and the PIGRET assay could detect mutagenicity of ENU much earlier than the RBC Pig-a assay.

Evaluation of a single-dose PIGRET assay for cisplatin in rats compared with the RBC Pig-a assay.

As a part of a collaborative study of the Pig-a assay by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagen Society, a genotoxicity study on cisplatin was performed using red blood cell (RBC) Pig-a and PIGRET assays. The dose levels were set at 0 (vehicle, physiological saline), 0.5, 1, and 2 mg/kg, and cisplatin was administered intravenously once to male F344 rats. The RBC Pig-a and PIGRET assays were performed using peripheral blood collected at pre-dosing and 1, 2 and 4 weeks after dosing. In the RBC Pig-a assay, an increase in the Pig-a mutant frequency (MF) was observed at week 4 in the high dose group. Although a significant increase in the Pig-a MF was also observed at week 2 in all cisplatin-treated groups, it was considered that this change was caused by a low MF in the vehicle control group and not to be biologically relevant. In the PIGRET assay, the Pig-a MF was increased at weeks 1, 2 and 4 in the high dose group. In addition, the means of the vehicle control group's Pig-a MFs in the PIGRET assay were lower than those in the RBC Pig-a assay. Based on the above results, cisplatin was determined to have mutagenicity under the conditions of this study, and it was demonstrated that the PIGRET assay was an appropriate tool to evaluate the in vivo mutagenicity much earlier than the RBC Pig-a assay.

The PIGRET assay, a method for measuring Pig-a gene mutation in reticulocytes, is reliable as a short-term in vivo genotoxicity test: Summary of the MMS/JEMS-collaborative study across 16 laboratories using 24 chemicals.

The in vivo mutation assay using the X-linked phosphatidylinositol glycan class A gene (Pig-a in rodents, PIG-A in humans) is a promising tool for evaluating the mutagenicity of chemicals. Approaches for measuring Pig-a mutant cells have focused on peripheral red blood cells (RBCs) and reticulocytes (RETs) from rodents. The recently developed PIGRET assay is capable of screening >1×106 RETs for Pig-a mutants by concentrating RETs in whole blood prior to flow cytometric analysis. Additionally, due to the characteristics of erythropoiesis, the PIGRET assay can potentially detect increases in Pig-a mutant frequency (MF) sooner after exposure compared with a Pig-a assay targeting total RBCs (RBC Pig-a assay). In order to test the merits and limitations of the PIGRET assay as a short-term genotoxicity test, an interlaboratory trial involving 16 laboratories was organized by the Mammalian Mutagenicity Study Group of the Japanese Environmental Mutagenicity Society (MMS/JEMS). First, the technical proficiency of the laboratories and transferability of the assay were confirmed by performing both the PIGRET and RBC Pig-a assays on rats treated with single doses of N-nitroso-N-ethylurea. Next, the collaborating laboratories used the PIGRET and RBC Pig-a assays to assess the mutagenicity of a total of 24 chemicals in rats, using a single treatment design and mutant analysis at 1, 2, and 4 weeks after the treatment. Thirteen chemicals produced positive responses in the PIGRET assay; three of these chemicals were not detected in the RBC Pig-a assay. Twelve chemicals induced an increase in RET Pig-a MF beginning 1 week after dosing, while only 3 chemicals positive for RBC Pig-a MF produced positive responses 1 week after dosing. Based on these results, we conclude that the PIGRET assay is useful as a short-term test for in vivo mutation using a single-dose protocol.

Circadian rhythms of resistance to UV-C and UV-B radiation in Euglena as related to "escape from light" and "resistance to light".

Radiation-induced stress, either from visible or UV light, is strongest at midday. We found that, in the absence of stress or time cues, Euglena gracilis Z was the most resistant to UV-C and UV-B at subjective midday, whether judged from immediate or reproductive survival. The circadian UV-resistance rhythms were free-running in stationary cultures under 1-h light/1-h dark cycles or continuous darkness, indicating that cell-cycle dependent DNA susceptibility to UV was not involved. We moreover examined what was the primary cause of the circadian UV resistance, estimated as the immediate cell survival. The half-maximal lethal dose (LD(50)) of UV-C at subjective midday (the most resistant phase) was 156 J/m(2), which is approximately 3-fold that at subjective midnight. The same was true for UV-B, except the LD(50) was approximately 13-fold that of UV-C. Temperature during UV irradiation had little effect, indicating that survival was not mediated via enzymatic reactions. Non-enzymatic antioxidants were added 5 min before UV irradiation. Dimethylsulfoxide (a hydroxyl radical scavenger) increased survival after UV-B, but had little effect after UV-C; conversely, sodium ascorbate increased survival after UV-C, but not after UV-B. These findings suggest that circadian rhythms of resistance to UVs involve a common mechanism for maximizing non-enzymatic antioxidative capacity at subjective midday, but the specific antioxidants differ.

Circadian gating of photoinduction of commitment to cell-cycle transitions in relation to photoperiodic control of cell reproduction in Euglena.

A novel type of circadian and photoperiodic control of the cell division cycle was found in photoautotrophic Euglena gracilis. When algae entrained to 24 h light-dark (LD) cycles (14 h L) were transferred to continuous darkness (DD) at the eighth hour of the final LD photoperiod, cell-cycle transition was arrested in phase G1, S or G2. The subsequent exposure of these dark-arrested cells to a 6 h light-break allowed the dark-arrested cells to undergo cell-cycle progression in DD, in a manner dependent on the circadian phase; maximum photoinduction occurred around dusk. Inhibitor experiments suggested that the photoinduced commitment of G2 cells to cell division required light for a signal originating in noncyclic photosynthetic electron transport (PET), particularly cytochrome b6-f but not for the metabolic energy required by the process. The fact that the circadian rhythm of photoinduction ran out-of-phase from that of noncyclic PET signaling suggests that the site of regulation by the former rhythm is downstream of noncyclic PET. The occurrence of maximum photoinduction around dusk suggests that the 'external coincidence' model of photoperiodic induction describes the activation of the photoinductive phase. Further evidence supporting this hypothesis is the relationship between cell reproduction and day length; the resulting sigmoidal curve indicates a combined effect of photosynthesizing period and circadian stimulation around dusk. Circadian control is shown to be an integral part of the mechanism for 24 h LD cycle-induced synchronous cell division.

Heterochronic spontaneous rupture of bilateral renal cell carcinomas in a hemodialysis patient.

A 64-year-old man undergoing chronic hemodialysis was admitted under a shock state with macrohematuria and fatigue lasting for two hours. A blood analysis revealed severe anemia. Computed tomography disclosed a large right-sided perirenal hematoma. The patient was successfully treated with radical nephrectomy, leading to a histological diagnosis of spontaneous rupture of renal cell carcinoma (RCC). One year after rupture of the right RCC, he again developed macrohematuria and computed tomography revealed a left-sided perirenal hematoma. Radical nephrectomy followed by a histological examination revealed spontaneous rupture of the left-sided RCC. This case emphasizes the importance of conducting periodic imaging evaluations of chronic hemodialysis patients with renal cystic masses.