AB0186 IMPROVEMENT OF RADIOGRAPHIC JOINT DESTRUCTION IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS IN THE LAST DECADE

Background

The paradigm shift has caused in the treatment for rheumatoid arthritis (RA) before the last decade [1]. The advent of high-dose MTX and biologics has maked it possible to treat RA with early and aggressive therapy, and prevent the joint destruction [2].

Objectives

To aim of this study, we investigated the joint destruction and clinical outcomes in patients with early RA every 5 years in the last decade.

Methods

81 patients with early RA (within 1 year from their onset of RA) enrolled retrospectively in this study. The number of patients with early RA were 21 in 2009, 23 in 2014, and 37 in 2019, respectively. They had 17 males and 64 females. Mean age was 59 years (19-92) at the first visit to our department. The following items were investigated: age, disease duration from onset to consultation, anti-cyclic citrullinated peptide antibody (ACPA) positivity (positivity was defined as >4.5 U/ml), CRP, DAS28CRP4, medications, and modified total sharp score (mTSS) at the time of initial consultation and 1 year later. Kruskal-Wallis test was used for statistics (PASW 25 software, SPSS Institute Inc., Chicago, IL, USA, p<0.05).

Results

The ACPA positivity rates were 71.4% (15/21) in 2009, 78.3% (18/21) in 2014, and 78.4% (29/37) in 2019, respectively. The mean value of DAS28CRP4 was 4.7 (2.4-6.8) in 2009, 4.2 (1.2-6.2) in 2014, and 4.2 (2.1-6.7) in 2019 at the time of the first visit to our department respectively. DAS28CRP4 under 2.6 was 29% (6/21) in 2009, 61% (14/23) in 2014, and 54% (20/37) in 2019 1 year after the first visit. The mean improvement of DAS28CRP4 (ΔDAS28CRP4) was -1.2 (-3.9 - 2.1) in 2009, -1.5 (-4.0 - 1.7) in 2014, and -1.7 (-4.1 - 0.4) in 2019, respectively. It had tended to improve gradually, however, it was not significantly different (p= 0.20, Figure 1).

Figure 1.

Mean value of improvement of mTSS and DAS28CRP4 (ΔmTSS and ΔDAS28CRP4) from initial visit to 1 year later at 2009, 2014 and 2019.

The changing of mTSS for a year (ΔmTSS) was 4.2 (0-17) in 2009, 0.9 (0-10) in 2014, and 0.6 (0-4) in 2019, respectivly. ΔmTSS in 2014 and 2019 was significantly lower compared to that in 2009 (p<0.05, Figure 1).

One year after the first visit to our department, the mean dose of MTX increased to 9.2 mg/week (2-14) in 2014 and 8.7 mg/week (4-16) in 2019 compared to 6.6 mg/week (2-8) in 2009 (p=0.19). The mean dose of PSL decreased 4.2 mg/day (1-8) in 2014, and 3.8 mg/day (1-10) in 2019 compared to 4.9 mg/day (2-10) in 2009, respectively (p=0.11). On the other hand, biological DMARDs were introduced in 24% (5/21) in 2009, 13% (3/23) in 2014, and 13% (1/37) in 2019, respectively.

Conclusion

Jonit destruction has been already reported to begin in patients with early-stage of RA [1, 2]. Based on the results of this study, joint desctruction in early RA was decreased in the last decade, because of more early and aggressive therapy for early RA with increasing mean dose of MTX gradually, not biologic DMARDs in real world. In addition, the mean dose of PSL in 2014 and 2019 decreased compared to that in 2009. The intensive therapy for early RA at our hospital has shown the improvement of joint destruction in the last decade.

References

[1]Emery P, Breedveld FC, Dougados M, et al. Early referral recommendation for newly diagnosed rheumatoid arthritis: evidence based development of a clinical guide. Ann Rheum Dis 2002;61:290–297.

[2]Smolen JS, Landewé RBM, Bijlsma JWJ, et al. EULAR recommendations for the management of rheumatoid arthritis with synthetic and biological disease-modifying antirheumatic drugs: 2019 update. Ann Rheum Dis 2020;79:685-699.

Disclosure of Interests

None declared

AB0181 RADIOGRAPHIC DESTRUCTION OF CARPAL BONE IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS

Background

The pharmacotherapy for rheumatoid arthritis (RA) has changed dramatically and caused a paradigm shift with the advent of methotrexate (MTX) and biological disease-modifying antirheumatic drugs (bDMARDs).

Before the paradigm shift of RA therapy, the frequency of carpal collapse was high in patients with RA.

It has been reported that certain numbers of patients with RA rapidly advance the destruction of the carpal bones during the early onset in the natural course of it [1].

Another report showed that hand function was positively correlated with disease activity[2]

In Japan, bDMARDs were approved in 2003, and the maximum allowable dose of MTX was raised from 8 mg/week to 12 mg/week in 2012.

We hypothesize early aggressive therapy for the patients with early RA may have improved outcomes of carpal bone destruction in this last decade.

In this study, we investigated the change of drug therapy and carpal height ratio (CHR) in patients with early RA in the last decade.

Objectives

The aim of this study was to investigate CHR and drugs for the patients with early RA who developed it and started the therapy in 2009, 2014, and 2019.

Methods

Patients with early RA diagnosed in our department in 2009, 2014, and 2019 were included in the study.

The CHR was measured at the first visit and two years later on radiographs of both hands.

The drug history for RA was obtained in the medical records retrospectively.

All statistical analyses were performed with EZR version 1.55.

Results

This study included 43 cases (36 females, 7 males). The number of cases in 2009, 2014, and 2019 was 16, 13, and 14, respectively.

The mean age at the time of initial examination was 55 years (30-72).

There was no significant difference in the mean value of DAS28-CRP at the time of the first visit in each year.

The left hand CHR of initial diagnosis was 0.554 (0.484-0.632), 0.551 (0.490-0.618), and 0.567 (0.517-0.632) in 2009, 2014, and 2019, respectively, with no significant difference.

Two years later, the left-hand CHR was 0.541 (0.475-0.651), 0.549 (0.502-0.617), and 0.562 (0.528-0.591), respectively, with no significant difference.

There was also no significant difference in the amount of change.

The right hand CHR of initial diagnosis was 0.525 (0.475-0.607), 0.539 (0.459-0.589), and 0.557 (0.506-0.635) in 2009, 2014, and 2019, respectively, with no significant difference.

Two years later, the right-hand CHR was 0.532 (0.444-0.627), 0.529 (0.478-0.588), and 0.548 (0.491-0.593), respectively, with no significant difference.

There was also no significant difference in the amount of change.

The DAS28-CRP of initial diagnosis for cases in 2009, 2014, and 2019 was 4.68 (3.11-6.83), 4.19 (1.21-6.15), and 4.23 (2.41-6.38), respectively.

The DAS28-CRP at 2 years after treatment for cases in 2009, 2014, and 2019 was 2.12 (0.96-3.60), 2.25 (1.13-4.81), and 2.04 (0.99-3.45), respectively.

Although DAS28-CRP was improved, there was no significance among the three groups.

The usage rate of MTX was 56.3% in 2009, 76.9% in 2014, and 50% in 2019, with mean doses of 6.2 mg (2-8 mg), 8.6 mg (4-12 mg), and 9.1 mg (4-16 mg), respectively. There was no significant difference in the rate and dosage of MTX use in each year.

bDMARDs were used in one case in 2009, two cases in 2014, and one case in 2019.

Conclusion

In this study, DAS28-CRP showed a trend of improvement in this decade, but there was no obvious improvement in the progression of carpal collapse.

Further early aggressive therapy may be necessary to prevent the destruction of the carpal bones.

References

[1]Ochi T, Iwase R, Yonemasu K, Matsukawa M, Yoneda M, Yukioka M, et al. Natural course of joint destruction and fluctuation of serum C1q levels in patients with rheumatoid arthritis. Arthritis and rheumatism. 1988 Jan; 31(1):37-43.

[2]Palamar D, Er G, Terlemez R, Ustun I, Can G, Saridogan M. Disease activity, handgrip strengths, and hand dexterity in patients with rheumatoid arthritis. Clinical rheumatology. 2017; 36(10):2201-2208.

Disclosure of Interests

None declared

Nutritional Status and Energy Intake as Predictors of Functional Status After Cardiac Rehabilitation in Elderly Inpatients With Heart Failure - A Retrospective Cohort Study

BACKGROUND

Whether the short-term effect of cardiac rehabilitation (CR) in elderly patients with heart failure (HF) is influenced by nutritional status is uncertain, so the present study investigated the effect of nutritional status on functional recovery after CR in elderly HF inpatients.Methods and Results:We enrolled 145 patients admitted for treatment of HF who were aged ≥65 years and had a low functional status defined as a Barthel index (BI) score ≤85 points at the commencement of CR. Nutritional status was assessed by the Mini Nutritional Assessment Short Form (MNA-SF) and total energy intake per day. The primary endpoint was functional status determined by the BI score at discharge. The median CR period was 20 days (interquartile range: 14-34 days), and 87 patients (60%) were functionally dependent (BI score ≤85) at discharge. Multivariate logistic regression analysis showed that MNA-SF score (odds ratio [OR]: 0.76, P=0.02) and total energy intake at the commencement of CR (OR: 0.91, P=0.02) were independent predictors of functional dependence after CR. MNA-SF score ≤7 and total energy intake ≤24.5 kcal/kg/day predicted functional dependence at discharge with moderate sensitivity and specificity.

CONCLUSIONS

MNA-SF score and total energy intake at the commencement of CR are novel predictors of the extent of functional recovery of elderly HF inpatients after in-hospital CR.

The transcribed-ultraconserved regions in prostate and gastric cancer: DNA hypermethylation and microRNA-associated regulation

The transcribed-ultraconserved regions (T-UCRs) are a novel class of non-coding RNAs, which are absolutely conserved (100%) between the orthologous regions of the human, rat and mouse genomes. Previous studies have described that several T-UCRs show differential expressions in cancers and might be involved in cancer development. We investigated the transcriptional levels of representative 26 T-UCRs and determined the regions that were differently expressed in prostate cancer (PCa) and gastric cancer (GC). A quantitative reverse transcription-polymerase chain reaction analysis revealed the downregulation of Uc.158+A expression by a DNA methylation-associated mechanism, which was restored by 5-Aza-dC (5-aza-2'-deoxycytidine) treatment. Bisulfite genomic sequencing using cell lines and tissue samples demonstrated cancer-specific CpG hypermethylation in both GC and PCa. However, Uc.416+A was only overexpressed in GC and we identified an miR-153 binding site in the possible regulatory region of Uc.416+A using online databases. Along with a forced expression or knockdown of miR-153 in MKN-74 GC cells, the transcriptional levels of Uc.416+A were significantly disturbed. A luciferase reporter gene assay supported the direct regulation of Uc.416+A expression by miR-153. Furthermore, Uc.416+A was associated with cell growth through the regulation of IGFBP6 (insulin-like growth factor-binding protein 6) in GC. These findings suggest an oncogenic role of Uc.416+A in GC, which suggests that our approach would provide new insights into functional studies of T-UCRs in cancer biology.

A case of polycystic ovary syndrome conceived by intracytoplasmic sperm injection following laparoscopic ovarian drilling

Polycystic ovary syndrome (PCOS) is a disease in which an ovulation disorder is the main cause of infertility. Clomifene citrate (CC) is the treatment of first choice for ovulation induction in PCOS. If ovulation cannot be induced by CC, then either laparoscopic ovarian drilling (LOD) or gonadotropin therapy is selected as a subsequent treatment. Assisted reproductive technology (ART) is indicated for women with PCOS, similar to other infertility patients, when pregnancy is not achieved by intrauterine insemination (IUI). In this study, we experienced a case of PCOS in which pregnancy was achieved by ART following LOD. The case pertains to a 26-year-old patient. She consulted our hospital with a chief complaint of primary infertility. IUI with administration of CC plus recombinant follicle-stimulating hormone (rFSH) was carried out; however, pregnancy was not achieved. Subsequently, ART was carried out. In the first attempt, the development of several follicles was observed under the gonadotropin releasing hormone (GnRH) agonist long protocol. However, a fertilized oocyte was not obtained. In the second attempt, an ovum could not be collected after CC-rFSH ovarian stimulation. In the third attempt, a good quality embryo could not be obtained under the GnRH antagonist protocol, and therefore pregnancy could not be achieved. We performed LOD using a harmonic scalpel for the purpose of preventing severe OHSS and improving the quality of embryos. Following the operation, ovarian stimulation was performed under the CC-rFSH-antagonist protocol. Eighteen follicles were aspirated, six oocytes were picked-up, and five oocytes were normally fertilized. As a result, four embryos from day 2 culture were cryopreserved. Cryopreserved-thawed embryo transfer was thereafter performed, and a single pregnancy was achieved. LOD is a clinically effective treatment for PCOS requiring ART.

Effusion and solid lymphomas have distinctive gene and protein expression profiles in an animal model of primary effusion lymphoma

Lymphoma usually forms solid tumours in patients, and high expression levels of adhesion molecules are observed in these tumours. However, Kaposi's sarcoma-associated herpesvirus (KSHV)-related primary effusion lymphoma (PEL) does not form solid tumours and adhesion molecule expression is suppressed in the cells. Inoculation of a KSHV-associated PEL cell line into the peritoneal cavity of severe combined immunodeficiency mice resulted in the formation of effusion and solid lymphomas in the peritoneal cavity. Proteomics using two-dimensional difference gel electrophoresis and DNA microarray analyses identified 14 proteins and 105 genes, respectively, whose expression differed significantly between effusion and solid lymphomas. Five genes were identified as having similar expression profiles to that of lymphocyte function-associated antigen 1, an important adhesion molecule in leukocytes. Among these, coronin 1A, an actin-binding protein, was identified as a molecule showing high expression in solid lymphoma by both DNA microarray and proteomics analyses. Western and northern blotting showed that coronin 1A was predominantly expressed in solid lymphomas. Moreover, KSHV-encoded lytic proteins, including viral interleukin-6, were highly expressed in effusion lymphoma compared with solid lymphoma. These data demonstrate that effusion and solid lymphomas possess distinctive gene and protein expression profiles in our mouse model, and suggest that differences in gene and protein expression between effusion and solid lymphomas may be associated with the formation of effusion lymphoma or invasive features of solid lymphoma. Furthermore, the results obtained using this combination of proteomics and DNA microarray analyses indicate that protein synthesis partly reflects, but does not correlate strictly with, mRNA production.

Pituitary-gonadal axis and secondary sex characters in the spontaneously masculinized pintail, Anas acuta (Anatidae, Aves), with special regard to the gonadotrophs

This paper describes some aspects of the pituitary gland, gonads, and secondary sex characters of unusual pintails, Anas acuta, found in the wild. They were demonstrated to be females with partially masculinized plumage; i.e., their plumage showed various degrees of intersex, but the genital organs, syrinx, and electrophoretic pattern of sex-specific DNA were of the female type. Their left ovary underwent a marked involution and was associated with the mesonephros (the Wolffian body), as was the degenerated right ovary. Neither testicular tissue nor ovotestis was found in the gonad of either side. The oviduct was anatomically normal and comparable to that of the control adult. The plasma concentration of estradiol-17beta (E2) was shown to be 5.7+/-0.5 (mean+/-SE)pg/ml in the masculinized birds, 7.0+/-0.7 pg/ml in control males, and 22.5+/-6.1 pg/ml in control females, whereas plasma testosterone (T) was below the detection level in all of the samples. As to the pituitary gland, hypertrophy and/or deformity of the pars distalis was evident in the majority of the masculinized birds. Among others, hyperactive gonadotrophs, mainly luteinizing hormone (LH)- and LH/follicle-stimulating hormone (FSH)-immunoreactive cells, were prominent in the entire gland; and typical signet ring cells (castration cells) or giant gonadotrophs were frequently observed. These changes in the gonadotrophs may have been caused by a feedback response to the physiologically ovariectomized condition in the masculinized birds. Causal factor(s) of the ovarian degeneration remain to be further investigated.

rDrak1, a novel kinase related to apoptosis, is strongly expressed in active osteoclasts and induces apoptosis

This is the first report of a novel serine/threonine kinase, rabbit death-associated protein (DAP) kinase-related apoptosis-inducing protein kinase 1 (rDRAK1), involved in osteoclast apoptosis. We searched for osteoclast-specific genes from a cDNA library of highly enriched rabbit osteoclasts cultured on ivory. One of the cloned genes has a high homology with human DRAK1 (hDRAK1), which belongs to the DAP kinase subfamily of serine/threonine kinases. By screening a rabbit osteoclast cDNA library and 5'-RACE (rapid amplification of cDNA ends), we obtained a full length of this cDNA, termed rDRAK1. The sequencing data indicated that rDRAK1 has 88.0, 44.6, 38.7, and 42.3% identity with hDRAK1, DAP kinase, DRP-1, and ZIP (zipper-interacting protein) kinase, respectively. To clarify the role of DRAK1 in osteoclasts, we examined the effect of three osteoclast survival factors (interleukin-1, macrophage colony-stimulating factor, and osteoclast differentiation-inducing factor) on rDRAK1 mRNA expression and the effect of rDRAK1 overexpression on osteoclast apoptosis. The results suggested that these three survival factors were proved to inhibit rDRAK1 expression in rabbit osteoclasts. After transfection of a rDRAK1 expression vector into cultured osteoclasts, overexpressed rDRAK1 was localized exclusively to the nuclei and induced apoptosis. Hence, rDRAK1 may play an important role in the core apoptosis program in osteoclast.

Different expression of hepatic and renal cytochrome P450s between the streptozotocin-induced diabetic mouse and rat

1. Since limited information is available about alterations of cytochrome P450 levels in diabetic animals other than rat, expression of P450s in the liver and kidney of the streptozotocin (STZ)-induced diabetic mouse was investigated. 2. The mRNA levels of CYP2B10, 3A11, 4A10 and 4A14 in the liver were increased in the STZ-induced diabetic mouse of both sexes. The CYP2B9 mRNA level was increased in the liver of the male diabetic mouse. These alterations were observed even at 2 weeks after administration. Insulin treatment restored these changes. The findings were consistent with changes reported in rat. 3. The levels of hepatic CYP1A2 and 2E1 and renal 2E1 and 4A did not change in the diabetic mouse at any time-point examined. No changes were seen in CYP2A- or 2C-related proteins in the diabetic mouse. These findings were in contrast to those in rat. 4. The results indicate that mouse P450s respond to insulin-dependent diabetes mellitus differently from those of the rat, and suggest that the expression of P450s in diabetes is not generally the same across animal species.

A novel female-specific member of the CYP3A gene subfamily in the mouse liver

Expression of a female-specific CYP3A in the adult mouse liver was observed on immunoblotting analysis. To characterize this cytochrome P450, we determined the primary structure of its cDNA and examined its expression profile. This cytochrome P450 consisted of 504 amino acids and showed 92, 68, 88, and 69% amino acid sequence identity with mouse CYP3A11, 3A13, 3A16, and 3A25, respectively, and was designated as CYP3A41, a new mouse CYP3A gene. In the female liver, levels of CYP3A41 mRNA expression were comparable to those of CYP3A11, the major CYP3A enzyme in the adult mouse liver. Expression of CYP3A41 mRNA was detected immediately after birth in the livers of animals of both sexes, but increased with age in females, whereas it was gradually reduced in males, resulting in predominantly female-specific expression in livers. Lesser amounts of CYP3A41 mRNA were detected in the kidneys of female mice, with traces in the stomach, ovary, and heart of female mice and in the testis of male mice. Gonadectomy and sex hormone treatment indicated that estradiol and testosterone were able to induce and suppress the expression of CYP3A41 mRNA in the liver, respectively. Among the classical CYP3A inducers, dexamethasone, rifampicin, and 3-methylcholanthrene did not affect the level of CYP3A41 mRNA in the liver of either sex. On the other hand, pregnenolone 16alpha-carbonitrile and phenobarbital suppressed CYP3A41 level to half that of untreated female mice. These observations indicated that CYP3A41 is a female-specific CYP3A and one of the major CYP3A forms in the female mouse liver.

Prognostic factors of chronic rhinosinusitis under long-term low-dose macrolide therapy

We studied the immunological and histopathological factors that affect the prognosis of chronic rhinosinusitis under long-term low-dose macrolide therapy. Sixteen patients with chronic rhinosinusitis were given 200 mg clarithromycin or 150 mg roxithromycin orally once a day without other concurrent treatments for 2-3 months. Measurement of the serum IgE level, blood cell count and differential leukocyte count of the peripheral blood, cytological assessment of the nasal smear and computed tomographic (CT) scans of the paranasal sinuses were performed before treatment. The opacity of the sinuses was estimated and scored by the CT images. After treatment, anterior ethmoidal mucosa samples were collected, an infiltrated inflammatory cells, interferon (IFN)-gamma-positive cells and interleukin (IL)-4-positive cells were examined histologically and immunohistochemically. The severity of nasal symptoms was scored before and after treatment, and the improvement rate of the score (symptomatic improvement rate) was calculated. Patients with normal levels of serum IgE (</=250 U/ml) showed a significantly higher symptomatic improvement rate than those with high levels of serum IgE (42.1 +/- 11.2 vs. 4.9 +/- 3.1%, p = 0.046). The symptomatic improvement rate was inversely correlated with the eosinophil counts in the peripheral blood (r = -0.51, p = 0.04), in the nasal smear (r = -0.54, p = 0.045) and in the sinus mucosa (r = -0.54, p = 0.02). Meanwhile, the CT score, the number of IFN-gamma-positive cells and IL-4-positive cells in the sinus mucosa and neutrophil counts in the nasal smear and in the sinus mucosa failed to correlate with the symptomatic improvement rate. These results suggest that macrolide therapy is indicated for patients without atopy or smear/tissue/peripheral blood eosinophilia. On the contrary, the severity of the disease, Th1/Th2 dominance in the sinus mucosa and neutrophilia are unlikely to be prognostic factors of chronic rhinosinusitis under long-term low-dose marolide therapy.

Generic tendency of metal salt cytotoxicity for six cell lines

Systematic cytotoxicity evaluation of various metallic elements may contribute to the development of new metallic biomaterials with superior biocompatibility. It is generally reported that the cytotoxicity of a chemical differs with cell lines. However, our previous study revealed a high correlation in the cytotoxicity of 43 metal salts between two murine cell lines. If there is any generic tendency toward metal salt cytotoxicity for many kinds of cells, that information is helpful for the determination of the chemical composition of new metallic biomaterials that are expected to have lower cytotoxicity. In this study, the cytotoxicity of 12 metal salts was evaluated using four cell lines, and the results were compared, including those for two other cell lines obtained in our previous study. A metal salt concentration that reduced cell viability to 50% of that without any metal salt (IC(50)) was used as an index to compare the metal salt cytotoxicity between cell lines. The correlation was statistically proved by the IC(50)s of 12 metal salts among these cell lines (p < 0.01), suggesting the existence of a generic tendency to metal salt cytotoxicity beyond cell lines. The metal salt order of toxicity from the highest was K(2)Cr(2)O(7), AgNO(3), VCl(3), SbCl(3), CuCl(2), CoCl(2), NiCl(2), ZnCl(2), Cr(NO(3))(3), FeCl(3), TiCl(4), and Al(NO(3))(3). The sensitivity for metal salt cytotoxicity differed with cell lines; IMR-32 had the highest sensitivity among the six cell lines.

Cytotoxicity evaluation of 43 metal salts using murine fibroblasts and osteoblastic cells

Metallic biomaterials are generally used for replacement of structural components of the human body such as bones, joints, and tooth roots. When they are implanted inside a body, metallic biomaterials may corrode and/or wear, releasing metal ions and debris which may have toxic effects on tissues and organs. Since it is important for biomaterials to have no toxicity against a living body, a systematic and quantitative evaluation of the cytotoxicity of metallic elements is required for the development of new metallic biomaterials with superior biocompatibility. In this study, the cytotoxicity of 43 metal salts were evaluated by the colony formation method using two kinds of cultured cells. The effects of the difference in valence numbers of metallic elements in the salts on cytotoxicity were examined. The cytotoxicity of the salts of metallic elements' oxo acids was also investigated. As a result, the intensity of metal salts' cytotoxicity tends to be quite similar between MC3T3-E1 and L929 (the correlation coefficient of metal salts' IC50s is 0.82). The intensity of metal salts' cytotoxicity depends on the kinds of metallic elements, their chemical states, and concentrations. The IC50 of the highest toxic salt is 1.36 x 10(-6) mol L-1, which differs four orders of magnitude from the IC50 of the lowest toxic salt. K2Cr2O7, CdCl2, VCl3, AgNO3, HgCl2, SbCl3, BeSO4, and InCl3 are high toxic salts in which IC50s are smaller then 10(-5) mol L-1 for both or either of the cell lines. HgCl, Tl(NO3)3, GaCl3, CuCl2, MnCl2, CoCl2, ZnCl2, NiCl2, SnCl2, IrCl4, TlNO3, CuCl, RhCl3, Pb(NO3)2, Cr(NO3)3 and Bi(NO3)3 are relatively high toxic salts in which IC50s are smaller than 10(-4) mol L-1 for both or either cell lines.

Isolation of cysteine protease in the crude mite extract, Dermatophagoides farinae

In order to study the relationship between cysteine protease and Der f I, which is one of the major allergens in the mite, Dermatophagoides farinae, isolation of cysteine protease was attempted using various column chromatographies. Both the potent cysteine protease activity and the allergenic activity were detected in the same fractions by anion exchange chromatography on a DEAE-Sephacel, gel chromatographies and chelating Sepharose 6B chromatography. In the double immunodiffusion test, the finally isolated fraction and rabbit anti-Der f I sera reacted to give a single precipitation line which fused completely with the precipitation line formed by Der f I and anti-Der f I sera. Sequence analysis for the first 10 N-terminal amino acids from cysteine protease and Der f I were identical. These results strongly suggest that cysteine protease of mites may be Der f I allergen and that measuring cysteine protease activity may possibly become a beneficial method for detecting Der f I allergens.