Discrimination of productive and non-productive cough by sound analysis

There are two types of coughs, productive and non-productive; the former is caused by excess airway secretions. The analysis of cough may provide important clues not only to aid diagnosis, but also for the selection of drugs for treatment. In this study, cough sounds recorded in a free acoustic field from patients with productive cough and non-productive cough due to chronic airway diseases were compared with those of voluntary cough of healthy subjects and were analyzed by sound spectrogram and time-expanded waveform. All cough sounds could be separated into two or three phases. The implementation of the novel technique to record cough sounds in the free acoustic field and to analyze the sounds of the high frequency range enable recognition of the characteristics of the cough sounds in phase 2 of the cough.

Ischemic preconditioning suppresses the noradrenaline turnover in the rat heart

OBJECTIVE

The mechanism by which ischemic preconditioning protects the heart is presumed to be related to the reduction of energy consumption during a subsequent myocardial infarction. Since the sympathetic nervous system enhances cardiac function and energy consumption, we investigated the relation between ischemic preconditioning and the turnover rate of noradrenaline (NA) in the rat heart.

METHODS

The effect of 3 cycles of 5-min occlusions of the rat left coronary artery on changes in arterial blood pressure and heart rate provoked by a subsequent 30 min of ischemia were examined until 60 min after reperfusion. The effect of 3 cycles of occlusions on the infarct size was also evaluated 60 min after reperfusion by comparing the infarcted area with the area at risk in these animals (6 per preconditioned and sham-operated group). The tissue concentration of NA during sustained ischemia was determined in the left ventricle, the intraventricular septum, and the right ventricle in the preconditioned and sham-operated groups. Changes in the turnover rate of NA after 3 cycles of occlusions were also evaluated by assessing the alpha-methyl-p-tyrosine-induced depletion of NA (n = 7 per group).

RESULTS

A series of transient occlusions reduced the infarct size 60 min after a sustained ischemia for 30 min. Arterial pressure and heart rate were not affected. The concentration of NA was decreased in the left ventricle 60 min after the onset of sustained ischemia in both the preconditioned and sham-operated groups. The treatment with alpha-methyl-p-tyrosine decreased the NA concentration in all regions of the heart in the sham-operated group after 60 min. However, the treatment with alpha-methyl-p-tyrosine did not deplete the NA concentration in both the occluded and nonoccluded regions in the preconditioned group.

CONCLUSIONS

Transient ischemia ameliorated the heart injury induced by a subsequent sustained ischemia, as assessed histologically. The activity of the sympathetic nervous system in all regions of the heart was reduced by transient ischemia in the left coronary vascular bed. These findings suggest that the inhibition of the sympathetic nervous system by the treatment of ischemic preconditioning takes part in the cardiac protection.

A clinical analysis of the recovery from sensory disturbance after sagittal splitting ramus osteotomy using a Semmes-Weinstein pressure aesthesiometer

A number of studies of evaluation methods for sensory disturbance after sagittal splitting ramus osteotomy (SSRO) are known. To compare postoperative sensory disturbances among patients in different hospitals, a highly reproducible and standardized sensory test is required. In the present study, we measured the tactile threshold in the region innervated by the mental nerves in 45 patients (90 sides) after SSRO using a Semmes-Weinstein pressure aesthesiometer. The percentage of recovery to the normal level defined by Bell was 72.2% at one week, 82.2% at 4 weeks, and 90.0% at 8 weeks after SSRO. The recovery process was evaluated by classifying the postoperative sensory disturbance into 5 grade levels according to Bell's interpretation scale. The results showed that the SW sensory test is useful for evaluation of the recovery process from sensory disturbance after SSRO. Some improvements of this test were also discussed.

Central island tongue flap

Pedicled tongue flaps have proved to be an effective method of repairing defects due to tissue loss in the oral cavity. Their central position, mobility, and excellent blood supply make their use feasible in a variety of sites. This paper describes the use and applications of central island tongue flaps to reconstruct defects of anterior floor of the mouth. This procedure was conducted at the Department of Oral and Maxillofacial Surgery, Medical University Hanover, introducing an improved surgical method and presenting the actual operation performed in our department. This method is considered superior for resurfacing the anterior floor of mouth defects because it is easy to perform and results in recovery of function and cosmetics.

HLA-DRB1 alleles and beta 2 glycoprotein I-dependent anticardiolipin antibodies in Japanese patients with systemic lupus erythematosus

OBJECTIVE

To investigate the association of HLA DRB1 alleles with beta 2 glycoprotein I (beta 2 GPI)-dependent anticardiolipin antibodies (aCL) in Japanese patients with systemic lupus erythematosus (SLE).

METHODS

One hundred and forty-five Japanese patients with SLE were studied. beta 2 GPI-dependent aCL was measured by enzyme-linked immunosorbent assays. DNA typing of the DRB1 alleles was performed by the polymerase chain reaction sequence specific oligonucleotide probe method.

RESULTS

beta 2 GPI-dependent aCL was positive in 29 (20.0%) out of 145 SLE patients. SLE patients with beta 2 GPI-dependent aCL had a significantly higher frequency or one or more of the clinical manifestations assumed to be associated with aCL, compared to those without beta 2 GPI-dependent aCL (p < 0.05). The frequency of DRB1*0901 was lower in SLE patients than in healthy subjects. SLE patients with beta 2 GPI-dependent aCL were significantly associated with DRB1*0901 as compared to those without beta 2 GPI-dependent aCL (41.4% vs 15.5%, p < 0.005, R.R. = 3.8), although the corrected P value was not significant.

CONCLUSION

A possible association of DRB1*0901 with Japanese SLE patients with beta 2 GPI-dependent aCL was found. This association indicates an association between the disease and the HLA-DR53 (DRB4)-bearing haplotypes in different ethnic groups.

Expression of costimulatory molecule CD80 on peripheral blood T cells in patients with systemic lupus erythematosus

OBJECTIVE

To investigate the expression of costimulatory molecule CD80 on T cells of peripheral blood mononuclear cells (PBMC) in patients with systemic lupus erythematosus (SLE).

METHODS

Monoclonal antibodies against CD80 were used for flow cytometry and expression of CD80 on PBMC was studied in 26 patients with SLE, 18 patients with rheumatoid arthritis (RA), 8 patients with mixed connective tissue disease (MCTD), and 22 healthy controls.

RESULTS

CD80 was detected on CD3+ and CD19+ cells in patients with SLE and it was significantly higher than that of controls. In patients with SLE CD80 was expressed on CD4+ T cells (8.05+/-5.45%), significantly higher than in RA and controls, but was not highly expressed on CD8+ T cells (1.67+/-2.87%). CD80+CD4+ T cell phenotype analysis revealed CD45RA-, CD45RO+, and CD25+, or HLA-DR+ activated T cells. The percentage of CD80+ cells in CD4+ cells increased in the active stage of SLE, and was significantly correlated with the SLE disease activity index.

CONCLUSION

CD80 can be expressed on activated CD4+ T cells in PBMC of patients with SLE in vivo and the appearance of these cells is associated with the disease activity in SLE.

Apoptosis of lymphocytes induced by glucocorticoids and relationship to therapeutic efficacy in patients with systemic lupus erythematosus

OBJECTIVE

Glucocorticoids (GCs) are the drugs of first choice for treatment of systemic lupus erythematosus (SLE). However, the disease in some patients is resistant to these agents. This study evaluated the possibility of a relationship between response to GC treatment and the rate of apoptosis in vitro, and also analyzed Bcl-2 and Fas expression on peripheral blood mononuclear cells (PBMC) from patients with SLE in relation to GC-induced apoptosis.

METHODS

Twenty-seven SLE patients and 13 normal controls were studied. Disease activity scores were determined before and after treatment and used to divide patients into 2 groups: GC-resistant and GC-responsive. Isolated PBMC were stimulated with anti-CD3 monoclonal antibodies, cultured with various concentrations of GC, and analyzed by alamar blue assay to determine the LC50, defined as the concentration of GC lethal to 50% of the cells. We measured the expression of CD4, CD8, Fas, and Bcl-2 by FACStar plus flow cytometry.

RESULTS

Lymphocytes in the GC-resistant group of SLE patients showed a significantly lower percentage of GC-induced apoptotic cells than did lymphocytes from the responsive group or from normal controls. The LC50 in the resistant group was significantly higher than that in normal controls or the responsive group. The lymphocytes remaining in the resistant group after GC treatment were mainly CD8+, with a high expression of Bcl-2. There was no significant difference in Fas expression between the GC-responsive and GC-resistant groups.

CONCLUSION

Determination of the LC50 may be useful in predicting the efficacy of GC treatment in SLE patients, and may be of use in considering other treatment options. CD8 and Bcl-2 double-positive lymphocytes that are insensitive to the apoptotic effect of GCs may play a role in the resistance to these agents in SLE patients.

Systemic mastocytosis with extensive polypoid lesions in the intestines; successful treatment with interferon-alpha

A 35-year-old female presented in 1989 with hepatosplenomegaly, but no conclusive diagnosis was established. From 1992, she experienced transient episodes of facial flushing and palpitations. Osteosclerotic change was detected radiologically. Colonoscopy revealed massive polypoid lesions. Mast cells were demonstrated in bone marrow smear and imprinted preparations of colon biopsy specimens by toluidine blue staining. Plasma concentrations of histamine and soluble c-kit were elevated. She was successfully treated with interferon-alpha and prednisolone, resulting in the disappearance of histamine-related attacks and a gradual decrease in tumor size. However, the remission was interferon dose dependent. This case was considered as systemic mastocytosis with massive polypoid colon lesions and showed the importance of maintenance therapy with interferon-alpha.

[Effects of bathing on lung mechanics in patients with severe COPD]

Although it is well known that the majority of patients with severe COPD complain of exacerbated dyspnea while taking a Japanese-style bath, the mechanism has not been elucidated. We therefore investigated changes in lung volume (LV) and SaO2 in 16 seated patients with severe COPD, receiving treated with home oxygen therapy (HOT), and in 10 healthy subjects (C) immersed to the navel (N) and to the shoulder (S). We then subdivided the COPD patients into 2 groups, A and B. Group A was composed of patients taking less than 2 L oxygen/min, while group B was taking equal to or greater than 2 L oxygen/min. Expiratory reserve volume (ERV) decreased with statistical significance (p < 0.05) while inspiratory capacity (IC) substantially increased as immersion progressed. However, changes in LV were smaller, as obstructive ventilatory changes progressed. It also appeared that a significant O2 desaturation occurred in patients with COPD when movement was associated with taking a bath. The drop in SaO2 during bathing was significantly improved after patients received instructions concerning posture, slow movements, and pursed-lip breathing. These findings suggest that immersion, such as when taking a Japanese-style bath, 1) may change various LV to a lesser degree than in healthy subjects because of previously existent airway obstruction in COPD, 2) may aggravate arterial desaturation through further impairment of the VA/Q imbalance, 3) instructions for COPD patients could improve, their condition while bathing and, 4) the 6 minute walking distance (6 MD) might be important in predicting the severity of arterial desaturation while COPD patients are immersed.

[Sleep apnea syndrome in Japan: analysis of pathophysiology and nasal continuous positive airway pressure effectiveness]

Forty eight Japanese sleep apnea syndrome (SAS) patients, whose apnea-hypopnea index (AHI) was more than 30 times/hr. from 5 university hospitals (46 males, 2 females) were enrolled in this study to analyze the characteristics of the disorder and the effectiveness of nasal continuous positive airway pressure (nCPAP) effectiveness. Although the severity of excessive daytime sleepiness (EDS), depressive state, and ventricular premature beats caused by SAS seemed milder in Japanese than reported Caucasian patients, the prevalences of hypertension and glucose intolerance were quite high: 50 and 30% respectively. Treatment with nCPAP for 3 months was completed in 41 of 48 enrollees, a compliance rate of 85.4%, which was substantially higher than studies from Western countries. nCPAP treatment normalized about 50% of hypertensive patients and more than half of glucose intolerant patients. Moreover, EDS, driving ability, the severity of arrhythmia, and so forth were all improved with nCPAP. We, therefore, conclude that 1) SAS could differ between Japanese Caucasians in terms of clinical features resulting from SAS and 2) treatment with nCPAP is effective and should be considered as first-line treatment for patients with moderate to severe SAS, as reported in Western countries.

Monoclonal anti-cardiolipin antibodies from New Zealand Black x New Zealand White F1 mice react to thrombomodulin

The reactivity with and affinity for thrombomodulin (TM) of monoclonal anti-cardiolipin Abs (MoaCL), derived from a New Zealand Black x New Zealand White F1 (NZB/W F1) mouse, were studied to investigate the pathogenicity of anti-cardiolipin Abs (aCL). Four of eighteen MoaCL were found to react with rabbit TM when examined using ELISA. These four MoaCL also reacted with synthetic peptide that included the epidermal growth factor-like domain of human TM, a binding site for thrombin. The reaction with TM of these four MoaCL was inhibited by bovine thrombin. When the affinity for TM of the MoaCL was determined, the dissociation constants (Kd) ranged from 4.8 x 10(-9) to 4.7 x 10(-8) M. By contrast, examination of the affinity for cardiolipin (CL) gave values from 8.3 x 10(-6) to 7.4 x 10(-5) M. Thus, these MoaCL reacted to TM with a higher affinity than to CL. Moreover, these MoaCL also bound to TM on HUVEC and down-regulated the expression level of TM on the surface of HUVEC due to internalization of TM. The binding of thrombin to TM is known to initiate rapid protein C activation, and complexes of activated protein C and protein S show anticoagulatory activity. Thus, the present studies suggest that certain pathogenic aCL cross-react with TM and induce down-regulation of TM on endothelial cells, followed by induction of thrombosis.

Molecular evolution of amphioxus fructose-1,6-bisphosphate aldolase

The cDNA for amphioxus fructose-1,6-bisphosphate (FBP)-aldolase was isolated and its nucleotide sequence was determined. In the cDNA, there existed a probable open reading frame comprising 1080 bp; hence, 359 amino acid residues were deduced. The amino acid sequence indicates the deletion of 4 residues from N-terminus, in comparison with the sequence of FBP-aldolase isozymes from other sources. There was only one FBP-aldolase gene, and one enzyme species corresponding, in the amphioxus; this is the first report of the existence of a single FBP-aldolase species in animals. Enzymatic studies of both native and the recombinant FBP-aldolase suggest that the amphioxus enzyme belongs to an ancestral class I type which is not discovered among vertebrate aldolase isozymes.

Detection of proliferating cell nuclear antigen (PCNA) in peripheral blood mononuclear cells and sera of patients with malignant lymphoma

Proliferating cell nuclear antigen (PCNA) was detected in the peripheral blood mononuclear cells (PBMC) of patients with malignant lymphoma (ML). Twenty-one of 27 patients with ML had PCNA expressing PBMC (5.25+/-4.75% cells), which tended to increase in the advanced clinical stage of ML. PCNA in PBMC extracts was detected in 11 of 16 patients (54.5+/-41.9 ng/ml). The percentage of PCNA-positive cells correlated significantly with the concentration of PCNA in PBMC extracts (P < 0.005). Serum PCNA was detected in 6 of 16 patients (160.1+/-141.1 ng/ml), but did not correlate with the number of PCNA-positive cells. In some cases, the concentration of serum PCNA increased after chemotherapy while the percent PCNA-positive cells decreased. Our finding indicate that detection of PCNA in PBMC appears to help monitoring the extent of disease in ML and the serum PCNA level may be used in therapeutic studies of lymphoma patients.

Detection of antibodies to a recombinant gag protein derived from human endogenous retrovirus clone 4-1 in autoimmune diseases

To investigate whether human endogenous retroviruses (HERV) contribute to autoimmune diseases, we prepared a recombinant p30gag protein derived from clone 4-1 of the HERV family, using a baculovirus-vector system. This p30gag protein (CA41B) was approximately 30 kDa, as expected, and reacted with antibodies for p30gag purified from both murine and feline leukemia virus. This result suggested that the antigenic determinant for p30gag was well conserved in CA41B. Analysis of serum antibodies to p30gag in patients with autoimmune diseases was done by Western blotting. CA41B detected anti-p30gag antibodies in 48.3% of systemic lupus erythematosus (SLE) patients, 35.0% of Sjögren's syndrome (SS) patients, and 33.3% of mixed connective tissue disease (MCTD) patients, whereas no anti-p30gag antibodies were found in healthy subjects. This suggested that HERV p30gag or other retroviral p30gag proteins possessing the same antigenic determinant as CA41B may play a role in these diseases. Although detection of antibodies to HERV p30gag in autoimmune diseases is indirect evidence that HERV proteins are involved, this study showed that patients with autoimmune diseases have antibodies to HERV p30gag using a recombinant HERV protein rather than synthetic peptides based on HERV or retroviral proteins of other species.

Range of antinuclear antibodies in "healthy" individuals

OBJECTIVE

To determine the range of antinuclear antibodies (ANA) in "healthy" individuals compared with that in patients with systemic lupus erythematosus (SLE), systemic sclerosis (SSc; scleroderma), Sjögren's syndrome (SS), rheumatoid arthritis (RA), or soft tissue rheumatism (STR).

METHODS

Fifteen international laboratories experienced in performing tests for ANA by indirect immunofluorescence participated in analyzing coded sera from healthy individuals and from patients in the 5 different disease groups described above. Except for the stipulation that HEp-2 cells should be used as substrate, each laboratory used its own in-house methodology so that the data might be expected to reflect the output of a cross-section of worldwide ANA reference laboratories. The sera were analyzed at 4 dilutions: 1:40, 1:80, 1:160, and 1:320.

RESULTS

In healthy individuals, the frequency of ANA did not differ significantly across the 4 age subgroups spanning 20-60 years of age. This putatively normal population was ANA positive in 31.7% of individuals at 1:40 serum dilution, 13.3% at 1:80, 5.0% at 1:160, and 3.3% at 1:320. In comparison with the findings among the disease groups, a low cutoff point at 1:40 serum dilution (high sensitivity, low specificity) could have diagnostic value, since it would classify virtually all patients with SLE, SSc, or SS as ANA positive. Conversely, a high positive cutoff at 1:160 serum dilution (high specificity, low sensitivity) would be useful to confirm the presence of disease in only a portion of cases, but would be likely to exclude 95% of normal individuals.

CONCLUSION

It is recommended that laboratories performing immunofluorescent ANA tests should report results at both the 1:40 and 1:160 dilutions, and should supply information on the percentage of normal individuals who are positive at these dilutions. A low-titer ANA is not necessarily insignificant and might depend on at least 4 specific factors. ANA assays can be a useful discriminant in recognizing certain disease conditions, but can create misunderstanding when the limitations are not fully appreciated.

[A case of reactive arthritis fallen after shigellosis infection]

A 25-year-old woman was admitted for general arthralgia in July, 1989. Reactive arthritis with arthralgia after Shigellosis was diagnosed by sex, localization of arthralgia and positive for HLA-B 27. Within 3 weeks after starting diclifenac sodium 75 mg/day, the arthralgia remitted. It has been reported that patients who are positive for HLA-B 27 have a more severe acute or chronic sacroiliitis, and our case may support this report.

Range of antinuclear antibodies in "healthy" individuals

OBJECTIVE

To determine the range of antinuclear antibodies (ANA) in "healthy" individuals compared with that in patients with systemic lupus erythematosus (SLE), systemic sclerosis (SSc; scleroderma), Sjögren's syndrome (SS), rheumatoid arthritis (RA), or soft tissue rheumatism (STR).

METHODS

Fifteen international laboratories experienced in performing tests for ANA by indirect immunofluorescence participated in analyzing coded sera from healthy individuals and from patients in the 5 different disease groups described above. Except for the stipulation that HEp-2 cells should be used as substrate, each laboratory used its own in-house methodology so that the data might be expected to reflect the output of a cross-section of worldwide ANA reference laboratories. The sera were analyzed at 4 dilutions: 1:40, 1:80, 1:160, and 1:320.

RESULTS

In healthy individuals, the frequency of ANA did not differ significantly across the 4 age subgroups spanning 20-60 years of age. This putatively normal population was ANA positive in 31.7% of individuals at 1:40 serum dilution, 13.3% at 1:80, 5.0% at 1:160, and 3.3% at 1:320. In comparison with the findings among the disease groups, a low cutoff point at 1:40 serum dilution (high sensitivity, low specificity) could have diagnostic value, since it would classify virtually all patients with SLE, SSc, or SS as ANA positive. Conversely, a high positive cutoff at 1:160 serum dilution (high specificity, low sensitivity) would be useful to confirm the presence of disease in only a portion of cases, but would be likely to exclude 95% of normal individuals.

CONCLUSION

It is recommended that laboratories performing immunofluorescent ANA tests should report results at both the 1:40 and 1:160 dilutions, and should supply information on the percentage of normal individuals who are positive at these dilutions. A low-titer ANA is not necessarily insignificant and might depend on at least 4 specific factors. ANA assays can be a useful discriminant in recognizing certain disease conditions, but can create misunderstanding when the limitations are not fully appreciated.

Lamprey fructose-1,6-bisphosphate aldolase: characterization of the muscle-type and non-muscle-type isozymes

To study evolutionary aspects of fructose-1,6-bisphosphate (Fru-1,6-P2) aldolase during deuterostomian evolution, we have purified and characterized aldolases from the muscle and liver of lamprey (Entosphenus japonicus). Aldolase from the skeletal muscle and liver was identified to be the muscle-type isozyme and the non-muscle-type isozyme that was encoded by cDNAs M8 and L3, respectively, as described previously (Zhang, R., Yatsuki, H., Kusakabe, T., Iwabe, Miyata, T., Imai, T., Yoshida, M., and Hori, K., J. Biochem. 117, 545-553, 1995). The muscle-type isozyme has properties similar to vertebrate aldolase A, while the non-muscle-type isozyme shows a similarity to bacterial class I aldolase and vertebrate aldolase C but not to aldolase B, the liver-type aldolase, in terms of kinetic parameters: the Kcat values toward Fru-1,6-P2 and Fru-1-P, the Fru-1,6-P2/Fru-1-P activity ratio, and the Km values toward these substrates. The two enzymes have tetrameric forms with a molecular mass of approximately 160,000 and have similar pH optimum. The muscle-type and non-muscle-type isozymes from the tissues show different electrophoretic mobility; the muscle-type isozyme moves much faster than the non-muscle-type isozyme toward anodic side. The recombinant muscle-type and non-muscle-type aldolases gave similar characteristics as those from the tissues. The results presented in this paper, together with the data presented in the previous paper, strongly suggest that in lamprey it is possible to have two types of aldolase isozymes rather than one or three isozymes.

Caenorhabditis elegans has two isozymic forms, CE-1 and CE-2, of fructose-1,6-bisphosphate aldolase which are encoded by different genes

Two distinct types of cDNAs for fructose-1,6-bisphosphate (FBP) aldolase, Ce-1 and Ce-2, have been isolated from nematode Caenorhabditis elegans, and the respective recombinant aldolase isozymes, CE-1 and CE-2, have been purified and characterized. The Ce-1 and Ce-2 are 1282 and 1248 bp in total length, respectively, and both have an open reading frame of 1098 bp, which encodes 366 amino acid residues. The entire amino acid sequences deduced from Ce-1 and Ce-2 show a high degree of identity to one another and to those of vertebrate and invertebrate aldolases. The highest sequence diversity was found in the carboxyl-terminal region that corresponds to one of the isozyme group-specific sequences of vertebrate aldolase isozymes that play a role in determining isozyme-specific functions. Southern blot analysis suggests that CE-1 and CE-2 are encoded by different genes. Concerning general or kinetic properties, CE-2 is quite different from CE-1. CE-1 exhibits unique characteristics which are not identical to any aldolase isozymes previously reported, whereas CE-2 is similar to vertebrate aldolase C. These results suggest that CE-2 might preserve the properties of a progenitor aldolase with a moderate preference for FBP over fructose 1-phosphate (F1P) as a substrate, whereas CE-1 evolved to act as an intrinsic enzyme that exhibits a much broader substrate specificity than dose CE-2.

Reference sera for antinuclear antibodies. II. Further definition of antibody specificities in international antinuclear antibody reference sera by immunofluorescence and western blotting

OBJECTIVE

To define the fine specificity of the 10 reference sera used for determination of antinuclear antibodies (ANA) and ANA subsets which are available from the Arthritis Foundation (AF) and from the Centers for Disease Control and Prevention (CDC).

METHODS

AF/CDC sera were assessed by experienced laboratory staff, using indirect immunofluorescence and Western blotting.

RESULTS

The original assignment of fluorescence patterns to 4 reference sera was confirmed, and the fluorescence intensities were determined using reference fluorescent beads. On Western blots, sera AF/CDC2 (anti-SS-B/La) and AF/CDC7 (anti-SS-A/Ro) did not detect Ro antigens, sera AF/CDC9 and AF/CDC10 appeared to be monospecific anti-Scl-70 and anti-Jo-1 sera, respectively, serum AF/CDC4 (anti-U1 small nuclear RNP) recognized the 70-kd band, and serum AF/CDC5 recognized the Sm antigen with its multiple bands. Semiquantitative analyses revealed that AF/CDC5, AF/CDC2, and AF/CDC10 were strongly reactive sera, whereas AF/CDC4 and AF/CDC9 were much weaker and should be used at lower dilutions on Western blots.

CONCLUSION

The AF/CDC ANA reference sera, originally described as reference reagents for indirect immunofluorescence and double immunodiffusion techniques, are also useful for Western blotting. The data presented herein further support the use of these sera for reference purposes.

A hidden immunoglobulin G2 in patients with rheumatoid arthritis detected by nuclear magnetic resonance

OBJECTIVE

The ratios of immunoglobulin (Ig) G1 and IgG2 in patients with rheumatoid arthritis (RA) were examined by nuclear magnetic resonance (NMR) and the results were compared to data obtained by ELISA.

METHODS

The IgG of 11 patients with RA were prepared with a DE-52 column and the specific signals for IgG1 and IgG2 were measured by NMR. The ratios of IgG1 and IgG2 were determined by the intensity of this signal. The samples were also measured by ELISA.

RESULTS

The ratios of IgG2 in patients with RA measured by NMR were increased significantly compared to controls. However, there were no significant differences in the data determined by ELISA. Thus, a discrepancy exists in the analysis of IgG2 ratios between NMR and ELISA methods.

CONCLUSION

There was a discrepancy in the IgG2 ratios of patients with RA between NMR and ELISA methods, and we attribute this to a conformational difference in IgG2 in patients with RA.