[SH/TA-508 clinical phase II study: dose evaluation of SH/TA-508 in echocardiography]

A cooperative study was conducted at 18 institutions to evaluate the safety and usefulness of SH/TA-508, a contrast medium for ultrasound diagnosis, and to find its optimum dose. One hundred and one patients with confirmed or suspected ischemic heart disease were examined with two-dimensional echocardiography, and 95 patients with mild mitral insufficiency were studied with the color Doppler method. The contrast medium was administered at low-dose (1.5-1.6g galactose) and high-dose (3.0-3.2 g galactose) levels at concentrations of 200, 300 and 400 mg/ml. The contrast effect was evaluated into five grades by two-dimensional echocardiography: - (ineffective), + (weak), 2+ (moderate), 3+ (good), 4+ (excessive effect) and into four grades with the color Doppler method, - (ineffective), + (weak), 2+ (optimum), 3+ (excessive effect). The two-dimensional echocardiographic studies showed effects graded at 2+ and above in most patients (83-93%). These findings were significantly more common in patients who had received the 300 and 400 mg/ml concentrations than in those who received the 200 mg/ml concentration. Statistical analysis found no significant differences between the high-dose and low-dose groups. Color Doppler echocardiography found signal enhancement graded at 2+ and above in 80-93% of cases. There were no significant differences in enhancement effect attributable to concentration or total dose. However, since excessive signal intensity was seen quite frequently, the dose levels in the present study were considered to be a little too high. Side effects includes transient feelings of warmth or cold, and the incidence of side effects was higher at higher doses and concentrations. The results show that the optimum concentration for two-dimensional echocardiography is 300 mg/ml and for color Doppler 200 mg/ml. No particular safety problems were seen with SH/TA-508, and this contrast medium is useful in echocardiography of the left ventricle and in enhancing mitral regurgitation signals in color Doppler examinations. Therefore, a phase III multicenter trial should be performed.

Effects of repeated doses of compound E for 4 and 9 weeks on the male reproductive organs

Results of two toxicity studies of Compound E, which is an anticancer drug, on male reproductive organs and fertility by oral repeated dosing at dose levels of 12.5, 25 and 50 mg/kg/day for 4 and 9 weeks in rats were compared. After repeated dosing, the male fertility was studied by mating with untreated female animals. At the dose of 50 mg/kg/day in the 4-week study, Compound E significantly decreased testes weight and number of epididymal sperm, caused histopathological changes in the testis and epididymis characterized by decreased germ cells, but did not affect fertility. The dose of 25 mg/kg/day in the 9-week study caused reduction in epididymal weight and number of epididymal sperm and histopathological changes in the testis. The dose of 50 mg/kg/day in the 9-week study was lethal and caused more prominent toxic effects in the reproductive organs and loss of fertility. The present studies suggest that the order of sensitivity of parameters on male reproductive organs is as follows; histopathological examination = organ weight > number of sperm in epididymis > pregnancy index> copulation index. Further, 4-weeks repeated dosing is of sufficient duration to predict adverse effects of test compounds.

[Change of the cognitive function after open heart surgery]

The changes of cognitive function after open heart surgery was examined using the Hasegawa's Dementia Scale (max. 30 points) in 47 patients with average age of 61.7 years. The patient's score was obtained preoperatively, and 1st and 7th postoperative days. Patients with postoperative scores above 24 points were classified as Non-Decline group, and those below 23 points as Decline group; comparative analyses were done on the relationship between various perioperative factors on both groups. Anesthesia was induced with low-dose fentanyl and isoflurane-nitrous oxide in oxygen. The average operating time was 331 minutes, and the cardiopulmonary bypass time was 108 minutes with normothermia. There were 31 Non-Decline cases, and 16 (34%) Decline cases on the 1st and 5 (10 %) on the 7th postoperative day. The largest decrease in the Decline group was seen on the 1st postoperative day, and there were 4 cases of dementia. The factors in which a significant difference was observed between the 2 groups were age, amount of transfusion, extubation time, preoperative complications and postoperative cardiac index, and these was not related to the operation or ECC time. Moreover there were high incidences of postoperative complications, especially LOS, in the Decline group. It was concluded that one of the largest contributing factors of abnormality of the cognitive function postoperatively was age, and other factors such as pre- and postoperative general conditions of the patients, especially cardiac function, might also be related. The length of hospitalization in the cases of decreased cognitive function was longer.

Confluent monolayers of bile duct epithelial cells with tight junctions

The culture of fully differentiated intrahepatic bile duct epithelial cells (IBDECs) to use as a model for the in vivo intrahepatic biliary tract has not been established. IBDECs from normal rat livers were grown on a collagen-coated permeable filter and formed a confluent monolayer 7 days after being plated. Positive reactions for cytokeratin-19 and retained gamma-glutamyl transpeptidase (GGTP) activity were shown. The transepithelial electrical resistance between the apical and the basolateral compartment culture chambers increased with the culture age and plateaued after the 7th day. The resulting cultured cells displayed a number of characteristics. (1) The cells formed a thin, continuous monolayer and displayed microvilli on the apical surface and junctional complexes between the cells, consistent with in vivo IBDECs. (2) Cells cultured for more than 7 days prevented the passage of horseradish peroxidase (HRP) and ruthenium red through paracellular pathways. (3) Seven-day-old cultures displayed a mean transepithelial electrical resistance of 137.3 omega-cm2, which decreased by 27.1% from its initial level after cell treatment with ethylenediamineteraacetic acid (EDTA). These results indicate that confluent IBDEC monolayers are well differentiated and polarized with tight junctions (TJs) between the cells. These cell monolayers can provide a useful and relevant model for the in vitro study of various in vivo bile duct phenomena.

[A case of interstitial pneumonia in polymyositis difficult to distinguish from gold pneumonitis]

Rheumatoid arthritis was diagnosed in a 48-year-old woman. She received a gold compound, and 4 weeks after the start of that therapy, interstitial pneumonia appeared. Findings from a muscle biopsy, and high serum CPK and LDH levels indicated that she suffered from polymyositis rather than rheumatoid arthritis. The result of a drug lymphocyte stimulation test (DLST) for the gold compound was more than 200%. Because the usefulness of the DLST for the gold compound in the diagnosis of gold pneumonitis is not thoroughly established, the DLST was also done in patients with rheumatoid arthritis who were receiving the gold compound without side effects, and in normal subjects. Many of the rheumatoid arthritis patients and some of the normal subjects had a positive response to the gold compound. Therefore a positive response on the DLST for the gold compound does not always support the diagnosis of gold pneumonitis.

A case of osteoporosis with bilateral defects in the mandibular processes

We carried out a detailed total body examination of a 62-year-old woman with osteoporosis who had bilateral defects in the mandibular processes. It was inferred that the defects in both articular heads were caused by resorption of small bone fragments following fracture. The quantity of bone salt was determined by microdensitometry, and a diagnosis of osteoporosis was then established. An improved bite was obtained by treatment consisting of tooth extraction and the preparation of partial dentures.

Dependency on the rate of change in PaO2 of the ventilatory response to progressive hypoxia

The biphasic nature of the ventilatory response to sustained hypoxia (< 1 h) is thought to occur as a result of combined effects of stimulation and depression with hypoxia. If the depressant effect of hypoxia on ventilation occurs later than the stimulatory effect, the magnitude of the ventilatory response to progressive hypoxia may be different according to the time required for a given fall in PaO2 during the test. In this study, we measured, in 10 healthy adult volunteers, ventilatory responses to isocapnic progressive hypoxia (HVR) using three different protocols (4 min, 6 min, and 15 min for SaO2 to decrease from the baseline to 80%) with or without pretreatment using theophylline (300 mg twice a day), an adenosine receptor antagonist, in a 2-d, single-blind crossover design. The slope values of HVR with the placebo were 0.31 +/- 0.04 (SE) (L/min/% fall of SaO2) in the 4-min protocol, 0.26 +/- 0.04 in the 6-min protocol, and 0.18 +/- 0.04 in the 15-min protocol. The HVR for the 15-min protocol was significantly lower than that for the 4-min or 6-min protocol. The HVR with theophylline was 0.46 +/- 0.08 for the 4-min protocol, 0.54 +/- 0.09 for the 6-min protocol, and 0.66 +/- 0.11 for the 15-min protocol, among which there were no significant differences. The dependency of HVR on the rate of change in PaO2, that was seen with a placebo run, disappeared after pretreatment with theophylline.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of the dextranase gene (dex) of Streptococcus mutans and its recombinant product in an Escherichia coli host

The gene (dex), which encodes the Streptococcus mutans dextranase (Dex), was cloned in Escherichia coli. The E. coli host harboring a recombinant plasmid (pSD2) containing an 8-kb BamHI insert produced a Dex protein of 133 kDa as well as smaller enzymes of 118, 104, and 88 kDa. The Dex produced by the recombinant E. coli was apparently located in the cytoplasmic fraction, not in the periplasmic nor the extracellular fractions. Subcloning and deletion analysis of pSD2 showed that the structural gene of Dex was encoded by a 4-kb BamHI-SalI fragment. The fragment also contained the dex promoter which was effective in the E. coli cell.

Suppression of multiple pulse formation in actively mode-locked laser diodes by gain quenching

We propose a new method for obtaining high-power short optical pulses without trailing pulses from an actively mode-locked laser diode. To quench the residual optical gain, a part of the output is reflected back into the laser diode with the orthogonal polarization and the appropriate time delay. A numerical analysis using travelingwave rate equations shows that trailing pulses caused by both the excess gain and the residual reflection at the laser diode facet are drastically suppressed.

[Function of the PTH/PTHrP receptor]

Cloning of the PTH/PTHrP receptor has established a new class of a receptor family which couples with G-proteins. When this receptor is occupied by PTH or PTHrP, activation of adenylate cyclase and phospholipase C occurs. Site-specific mutagenesis is extensively employed to study the structure-function relationship. The mechanisms whereby PTH/PTHrP receptor level is regulated are also being studied. PTH/PTHrP receptor knock-out and PTHrP knock-out mice show similar skeletal abnormalities but the former apparently die earlier before birth. There are still many problems to be elucidated, such as the reason for the subtle difference of PTH action and PTHrP action, and the role that this receptor plays in the pathogenesis of pseudohypoparathyroidism Ib.

[Optic neuropathy in systemic lupus erythematosus (SLE)--analysis of 54 cases including our case]

A 46-year old woman with systemic lupus erythematosus (SLE) who had been treated with oral administration of prednisolone (7.5 mg/5 mg on alternate days) at our outpatient clinic suddenly developed a loss of visual acuity, visual field defect, and photophobia on Dec. 15th, 1993. When she was admitted three days later, she was diagnosed as having optic neuropathy, and immediate treatment with methylprednisolone (1 g/day for three days) followed by prednisolone (50 mg/day) resulted in complete disappearance of the above symptoms by Feb. 9th, 1994. As far as we know, fifty-three cases of SLE with optic neuropathy have been reported previously. The result of analysis of the 54 cases including our case indicates that rapid diagnosis and corticosteroid treatment in an early phase of optic neuropathy leads to significant improvement.

Weber-Christian disease with benign cytophagic histiocytes in the skin lesion

We describe an 8 year old female with Weber-Christian disease who manifested erythema on her legs and an intermittent high fever. A wedge skin biopsy revealed lobular panniculitis and bean-bag cells, which were characteristic to cytophagic histiocytic panniculitis (CHP). However, she showed no evidence of liver dysfunction, hyperlipidemia, or coagulation disorders usually seen in CHP. Moreover, she responded well to oral corticosteroids therapy with resultant advanced subcutaneous fat atrophy.

HTLV-I from Iranian Mashhadi Jews in Israel is phylogenetically related to that of Japan, India, and South America rather than to that of Africa and Melanesia

A new endemic focus of human T-lymphotropic virus type I (HTLV-I) was recently reported among Mashhadi Jews, a group of immigrants from northeastern Iran to Israel. We extracted DNAs from fresh peripheral blood mononuclear cells (PBMCs) and/or gargle mouthwash from 10 HTLV-I carriers, who consisted of members of one family, and HTLV-I-associated myelopathy (HAM) and adult T-cell leukemia (ATL) patients. Long terminal repeat (LTR) regions of proviral DNAs were sequenced and analyzed phylogenetically. In a phylogenetic tree, all the Mashhadi HTLV-I isolates belonged to subtype A, one of the three subtypes of the cosmopolitan type of HTLV-I, and made a tight cluster distinct from the other isolates of subtype A from Japan, India, the Caribbean Basin, and South America. Although a few nucleotide substitutions were observed among the clones sequenced, no characteristic sequence variation was found in different disease manifestations, even in one family or different sources of DNA preparation.

The rationale for using logarithmic transformation of concentration data in toxicokinetic studies

The present paper focuses on the necessity of logarithmic transformation of plasma concentration in toxicokinetic studies. The dose-plasma concentration relationship is the most important subject to be studied, because test doses rise over a wide range from therapeutic dose level to toxic dose level in toxicity studies. It is concluded that the logarithmic transformation of concentration data effectively stabilized the variances, and the regression analysis of log-transformed data makes it possible to quantitatively evaluate the magnitude of non-linear kinetics of test compounds in toxicity studies.

Development of non-invasive fetal DNA diagnosis from maternal blood

Several attempts have been made to detect and retrieve fetal nucleated cells including nucleated erythrocytes (NRBCs), leukocytes, and trophoblasts in maternal blood. We have recently developed a new method for non-invasive fetal DNA diagnosis from maternal blood. Peripheral blood granulocytes including NRBCs were isolated by a discontinuous density gradient method using Percoll (Pharmasia). NRBCs were found and retrieved at a single cell level using a micromanipulator under a microscope. To determine whether the origin of the NRBCs was maternal or fetal, the NRBCs were analysed by polymerase chain reaction (PCR) amplification to determine the presence of a Y-chromosome-specific repeat sequence in mothers carrying male fetuses. We were successful in predicting fetal sex accurately in 10 out of 11 samples taken from maternal blood. This new technique opens up fetal DNA diagnosis from maternal blood during the first trimester of pregnancy to the whole population because there is no risk to the fetus or the mother.

Hypercalciuria and nephrocalcinosis in patients with idiopathic low-molecular-weight proteinuria in Japan: is the disease identical to Dent's disease in United Kingdom?

Idiopathic low-molecular-weight (LMW) proteinuria is a newly described renal disease in Japan and Italy. We report on 7 patients who manifested bilateral or unilateral nephrocalcinosis, as demonstrated by abdominal computed tomography scans. Renal histology revealed calcinosis of renal tubules in 2 patients. Computed tomography is a reliable method for the detection of nephrocalcinosis in this disorder. Hypercalciuria was also seen in 6 patients. A calcium-loading test performed in 2 patients suggested that hypercalciuria was of renal origin. Although the true pathogenesis is still not known, hypercalciuria and nephrocalcinosis appear to be a common complication in patients with idiopathic LMW proteinuria. These complications and clinical features suggest that idiopathic LMW proteinuria in Japan is likely to be identical to Dent's disease in the United Kingdom.

Hand-arm vibration in tropical rain forestry workers

Working conditions and health hazards including vibration syndrome related to forestry work using chain-saws were studied in Papua New Guinea and Indonesia. The subjects comprised 291 workers including 97 chain-saw operators. The health examination consisted of peripheral circulatory and sensory tests in the upper extremities. The vibration spectrum measured at the handle of the chain-saw indicated that these acceleration levels would lead to a moderately high risk of hand-arm vibration syndrome (HAVS). The peripheral circulatory function tests revealed dysfunction after more than five years vibration exposure. However, in general, the results of the function tests and subjective complaints showed fewer health problems compared to those of Japanese forestry workers. The reason of such differences of vibration effects seem to be the following: (1) warmer climate (more than 25 degrees C throughout the year), (2) young workers and short work experience. (3) short time vibration exposures on working days in the natural forests, (4) seasonal changes in logging work (5) healthy workers effects. Thus, we found no clear evidence that the workers of our study suffered from HAVS. A principal component analysis was applied. The factor score of the components of the reactive dynamics of peripheral circulation differed significantly after more than five years' exposure. On the other hand, we cannot deny the possibility that subclinical dysfunction of peripheral circulation may be caused by chain-saw operation in the tropics in future. Further investigations on the HAVS among forestry workers in the tropic environment are needed.

A limited sampling model for estimating pharmacokinetics of CPT-11 and its metabolite SN-38

The objective of this study was to develop a limited sampling model (LSM) to estimate the area under the curve (AUC) of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) and that of 7-ethyl-10-hydroxycamptothecin (SN-38) as predictive pharmacokinetic variables for leukopenia and episodes of diarrhea induced by CPT-11 administration. The model was developed with a training set consisting of pharmacokinetic studies in 36 patients who received a 90-min i.v. infusion of CPT-11 at a dose of 100 mg/m2. A multiple regression analysis of CPT-11 or SN-38 concentrations observed at each time point in the training set was used to predict the AUC of CPT-11 or SN-38. The final sampling models using only two time points were: AUCCPT-11 = 3.7891*C2.5 + 14.0479*C13.5 + 1.5463 AUCSN-38 = 0.5319*C2.5 + 19.1468*C13.5 + 72.7349 where C2.5 and C13.5 are the plasma concentration of CPT-11 (micrograms/ml) or SN-38 (ng/ml) at 2.5 and 13.5 h after the initiation of CPT-11 infusion, respectively. The models were validated prospectively on a separate test data set of 12 patients receiving the same dose of CPT-11 investigated in a previous study. Validation of the final LSM on the test data set gave values of root mean square error (RMSE) of 12.72% and 5.97% for the AUC of CPT-11 and that of SN-38, respectively. The model can be used to monitor the AUCs of both CPT-11 and SN-38 for the early prediction of toxicities and to establish a pharmacokinetically based dose modification strategy for safe administration of CPT-11.

Pharmacological correlation between total drug concentration and lactones of CPT-11 and SN-38 in patients treated with CPT-11

The pharmacokinetics of 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) and its active metabolite, 7-ethyl-10-hydroxycamptothecin (SN-38), were examined to establish the pharmacokinetic variability of the active lactones of CPT-11 and SN-38 in comparison with that of the total (lactone and carboxylates) plasma CPT-11 and SN-38. Twelve patients with malignancies were entered in the study. All received 100 mg/m2 of CPT-11 by intravenous drip infusion over 90 min. Blood was sampled at 10 time points in heparin-containing syringes. Analysis by high-performance liquid chromatography showed that the ratio of CPT-11 lactone to total CPT-11 concentration was highest (66%) just after the end of infusion and gradually decreased to 30% at 24 h. Almost 70% of SN-38 lactone was detected after the end of infusion and this decreased to 50% within 24 h. The standard errors of percent lactone of CPT-11 of SN-38 to total drug concentration at each sampling point were less than 12%. The area under the concentration-time curve (AUC) of total CPT-11 and that of total SN-38 were significantly correlated with the AUCs of the lactone CPT-11 and those of lactone SN-38, respectively. We conclude that, for practical purposes, monitoring of total CPT-11 and SN-38 has essentially the same clinical significance as monitoring of lactone CPT-11 and SN-38.

[Changes in intellectual function during perioperative period evaluated by Hasegawa's Dementia Scale]

In 190 patients, we studied changes in intellectual status during perioperative period using Hasegawa's Dementia Scale (HDS-R), and analyzed preoperative, intraoperative, and postoperative risk factors. HDS-R is one of the most popular scoring tests for evaluating dementia or delirium. Risk factors impairing preoperative score were aging, and preoperative complications including cerebral vascular disease, old myocardial infarction, arrythmia, and diabetes mellitus. Risk factors impairing postoperative score were, in addition to above-mentioned factors, hypoproteinemia and postoperative stressful conditions such as prolonged fever, pain, bed rest, and naso-gastric tube. In the patients who showed postoperative score deterioration, the incidence of old myocardial infarction, hypertension, and postoperative stressful conditions was significantly greater. In the patients who showed postoperative score improvement, local anesthesia including epidural and spinal anesthesia was used more often. In conclusion, aging or preoperative complications such as cerebral vascular disease, old myocardial infarction, arrythmia, and diabetes mellitus are high risks for the development of postoperative dementia and delirium under general surgical procedures and general anesthesia. Intraoperative management with patients awake using local anesthesia and postoperative stress-less conditions are important to avoid postoperative dementia.

Stress-induced cell surface expression and antigenic alteration of the Ro/SSA autoantigen

Recent studies have shown that Ro/SSA autoantigen is heterogeneous. There are two isoform families; the 60 kD forms (Ro60) and the 52 kD forms (Ro52). Recently we have found that autoantibodies to the Ro/SSA proteins are conformation dependent. Anti-Ro60 antibodies are mainly directed to the native protein and conversely anti-Ro52 antibodies are directed only to the denatured protein. It has been known that UV irradiation to cultured keratinocytes induces cell surface expression of Ro/SSA and this phenomenon has been thought to be related with photosensitivity in patients with anti-Ro/SSA antibodies. We studied the quantitative and qualitative changes of the Ro/SSA protein induced by stress, such as with heat shock and UV irradiation, and found that only Ro52 could be expressed on the cell surface of human peripheral lymphocytes by either heat shock or UV irradiation. Moreover, flow cytometric analysis revealed that HS-treated and UV-treated lymphocytes could be stained with patient sera, and by using a technique which combined immunoprecipitation and Western immunoblotting, it has been confirmed that Ro52 expressed on the cell surface can be recognized by anti-Ro/SSA antibodies in native form while cytoplasmic Ro52 cannot be recognized. These data suggest that Ro52 can be antigenic in vivo when expressed on the cell surface and may explain the mechanism of direct tissue damage by anti-Ro/SSA antibodies.

Lymphoepithelial cysts in the mediastinum with an opening to the trachea

A case of lymphoepithelial cysts (LECs) in the mediastinum, manifested radiographically by paratracheal air collection, is reported. Percutaneous injection of radiopaque material and indocyanine green into a cyst showed an opening to the trachea. During surgical resection, three well-circumscribed cysts were isolated. Pathologically the cysts were lined by a ciliated columnar epithelium and surrounded by lymphoid tissue with germinal centers. Judging from the level of the duct opening onto the airway, these LECs might have derived from a remnant of the fourth branchial pouch. To the authors' knowledge, this is the first case described.

[Usefulness of twenty-four-hour home monitoring of oxygen saturation in patients with chronic obstructive pulmonary disease]

The clinical usefulness of 24 hr home monitoring of oxygen saturation (SaO2) with pulse oximeter was studied in 48 outpatients with COPD. In addition, doppler echocardiography for measurement of acceleration time (AcT), which inversely correlates with mean pulmonary arterial pressure, a 6-minute walk test, and an exercise study on a bicycle ergometer were performed in 26, 17, and 14 patients, respectively. Nadir SaO2 and the total time during which SaO2 was below 90% were calculated to estimate diurnal and nocturnal oxygen desaturation (diurnal nadir SaO2, diurnal TSaO2 < 90%, nocturnal nadir SaO2, and nocturnal TSaO2 < 90%). Relations between the indices of desaturation measured during home monitoring and dyspnea grade (Fletcher-Hugh-Jones), awake PaO2, AcT, Hb, Ht, and oxygen desaturation during the exercise tests were also studied. Diurnal nadir SaO2 was lowest and diurnal TSaO2 < 90% was longest in the group with dyspnea grade IV. In the other groups, various degrees of oxygen desaturation were observed, even within groups. Diurnal nadir SaO2 and nocturnal nadir SaO2 correlated with awake PaO2, but not with diurnal TSoO2 < 90%. Diurnal nadir SaO2 was similar to nadir SaO2 during the exercise tests. AcT, hemoglobin, and hematocrit correlated with diurnal oxygen desaturation but not with nocturnal oxygen desaturation. From the above findings, we conclude that pulmonary hypertension may be associated with diurnal oxygen desaturation, and that home monitoring of SaO2 is useful for the detection of oxygen desaturation not predicted from dyspnea grade and PaO2 while awake.

A redox factor protein, ref1, is involved in negative gene regulation by extracellular calcium

A rise in extracellular calcium (Ca2+e) suppresses not only secretion of parathyroid hormone (PTH) but also expression of the PTH gene to ensure constant plasma Ca2+ level. A nuclear protein(s) in a wide variety of cells bound to the specific DNA elements (negative Ca2+ responsive elements, nCaREs) in the human PTH gene in sequence-specific and Ca2+e concentration-dependent manners. Our Southwestern cloning revealed that a redox factor protein (ref1), which was known to activate several transcription factors via alterations of their redox state, belonged to an nCaRE binding protein. The level of ref1 mRNA as well as of its protein was elevated by an increase in Ca2+e concentration. In gel shift assay, anti-ref1 antibody eliminated formation of the nCaRE-protein complex. We also found that there was another protein(s) interacting with nCaREs and ref1. Further, experiments with an antisense-ref cDNA expression vector introduced into cultured cells suggested that DNA (nCaRE)-ref1 interaction led to Ca2+e-mediated transcriptional suppression. Thus, it is concluded that ref1 possesses transcription repressor activity in addition to its function as a transcriptional auxiliary protein.