Parallel-stranded DNA under topological stress: rearrangement of (dA)15.(dT)15 to a d(A.A.T)n triplex

DNA oligonucleotides with appropriate sequences can form a stable duplex in which the two strands are paired in a parallel orientation instead of as the conventional antiparallel double helix of B-DNA. In parallel-stranded DNA (ps-DNA) base pairing is noncanonical with the glycosidic bonds in a trans orientation. The two grooves are equivalent. We have synthesized DNA duplexes consisting of a central parallel-stranded (dA)15.(dT)15 tract flanked by normal antiparallel regions, and ligated them into the pUC18 plasmid. The effect of negative supercoiling on the covalently closed circular molecules was studied by two-dimensional agarose gel electrophoresis and by chemical modification with OsO4-pyridine (Os,py) and diethylpyrocarbonate (DEPC). The following results were obtained: (i) The ps insert, and by inference ps-DNA in general, adopts a right handed helical form. (ii) Upon increasing the negative superhelix density (-sigma) to greater than 0.03 the 15 bp ps insert undergoes a major transition leading to a relaxation corresponding to a reduction in twist of approximately 2.5 helical turns. The transition free surgery is approximately kcal/mol. (iii) The chemical modification pattern of the resulting structure suggests that the purine strand folds back and associates with the pyrimidine strand, forming a novel intramolecular triplex structure consisting of d(A.A.T) base triplets. A model for the triplex conformation is proposed and its thermodynamic properties are analyzed by statistical mechanics.

Early undifferentiated connective tissue disease. I. Early clinical manifestation in a large cohort of patients with undifferentiated connective tissue diseases compared with cohorts of well established connective tissue disease

We identified a cohort of 410 patients with connective tissue disorders (CTD) of less than or equal to 1 year duration among the participating clinics of the Cooperative Systematic Studies of the Rheumatic Diseases Program. Fifty-seven had rheumatic arthritis (RA), 57 systemic lupus erythematosus, 37 poly/dermatomyositis, 46 scleroderma, and 213 early undifferentiated CTD, including patients with Raynaud's phenomenon, unexplained polyarthritis or at least 3 CTD manifestations such as rashes, myalgias, etc. Baseline clinical data are now being reported. The followup of these patients may prove to be valuable in understanding these diseases. To our knowledge no similar cohort of patients is available for further investigation.

Early undifferentiated connective tissue disease. II. The frequency of circulating antinuclear antibodies in patients with early rheumatic diseases

The presence of antinuclear antibodies (ANA) in the serum is a common finding in various connective tissue disorders, but usefulness of these antibodies in making diagnoses or prognoses is not known. We report the results of a panel of ANA determinations including ANA, anti-dsDNA, Sm, RNP, SSA, SSB, Jo-1, Scl-70 and PM-1 in 410 patients in a 5-year descriptive study of 410 patients with rheumatic disease symptoms of less than one year's duration. While some patients met diagnostic criteria for a specific rheumatologic diagnosis, others were classified as undifferentiated connective tissue disease (UCTD) and were subclassified by a constellation of symptoms. Our results show that ANA is sensitive in systemic lupus erythematosus (SLE) and progressive systemic sclerosis even in early disease but is not specific. Other "specific" autoantibodies were seen most frequently in SLE but were relatively insensitive and were seen in low frequency in UCTD. ANA have limited diagnostic value in patients with early disease. The prognostic value of these tests will be assessed as the prospective study of these cohorts progresses.

Intracellular Ca2+ stores in chicken Purkinje neurons: differential distribution of the low affinity-high capacity Ca2+ binding protein, calsequestrin, of Ca2+ ATPase and of the ER lumenal protein, Bip

To identify intracellular Ca2+ stores, we have mapped (by cryosection immunofluorescence and immunogold labeling) the distribution in the chicken cerebellar cortex of an essential component, the main low affinity-high capacity Ca2+ binding protein which in this tissue has been recently shown undistinguishable from muscle calsequestrin (Volpe, P., B. H. Alderson-Lang, L. Madeddu, E. Damiani, J. H. Collins, and A. Margreth. 1990. Neuron. 5:713-721). Appreciable levels of the protein were found exclusively within Purkinje neurons, distributed to the cell body, the axon, and the elaborate dendritic tree, with little labeling, however, of dendritic spines. At the EM level the protein displayed a dual localization: within the ER (rough- and smooth-surfaced cisternae, including the cisternal stacks recently shown [in the rat] to be highly enriched in receptors for inositol 1,4,5-triphosphate) and, over 10-fold more concentrated, within a population of moderately dense, membrane-bound small vacuoles and tubules, identified as calciosomes. These latter structures were widely distributed both in the cell body (approximately 1% of the cross-sectional area, particularly concentrated near the Golgi complex) and in the dendrites, up to the entrance of the spines. The distribution of calsequestrin was compared to those of another putative component of the Ca2+ stores, the membrane pump Ca2+ ATPase, and of the ER resident lumenal protein, Bip. Ca2+ ATPase was expressed by both calciosomes and regular ER cisternae, but excluded from cisternal stacks; Bip was abundant within the ER lumena (cisternae and stacks) and very low within calciosomes (average calsequestrin/Bip immunolabeling ratios were approximately 0.5 and 36.5 in the two types of structure, respectively). These results suggest that ER cisternal stacks do not represent independent Ca2+ stores, but operate coordinately with the adjacent, lumenally continuous ER cisternae. The ER and calciosomes could serve as rapidly exchanging Ca2+ stores, characterized however by different properties, in particular, by the greater Ca2+ accumulation potential of calciosomes. Hypotheses of calciosome biogenesis (directly from the ER or via the Golgi complex) are discussed.

Evidence against a laminin receptor role for calsequestrin

Calsequestrin, a muscle calcium binding protein, has been shown to bind the extracellular matrix protein laminin and evidence has been presented that CAL (initially called aspartactin) is on the cell surface, consistent with a role as a laminin receptor (1). In this report, we present evidence that does not support a laminin receptor function for CAL. We found that CAL immunoreactivity could not be detected on live cultured chick myotubes unless they were permeabilized with detergent. Furthermore, polyclonal anti-CAL antibodies did not perturb myotube adhesion to laminin or the rate of myoblast fusion on laminin. Expression of the CAL cDNA in a melanoma cell line that was poorly adherent to laminin did not increase adhesion to laminin. In these cells, CAL could not be detected on the cell surface, and the majority of CAL was found to be secreted into the media.

Selective in vivo removal of rheumatoid factor by an extracorporeal treatment device in rheumatoid arthritis patients

A prospective phase II trial was conducted to assess the feasibility, tolerance, and efficacy of a device designed for selective removal of rheumatoid factor from the plasma of rheumatoid arthritis patients. The device contained terpolymer hydrogel-coated plates with chemically attached, aggregated human immunoglobulin G, and it operated as an immunoaffinity column. Sixty-one patients aged 25 to 73 underwent weekly plasmapheresis treatments (the primary therapy phase). During the trial, patients continued current rheumatoid arthritis medications without dose adjustments. All patients received two to six treatments (primary therapy). Responding patients were eligible to continue apheresis treatment every 2 to 6 weeks (maintenance therapy). No serious, untoward side effects were noted in the course of this study; of 640 treatments, only 2 (in different patients) were aborted, one because of complaints of dizziness and angioedema and the other because of chest tightness and shortness of breath. Except for a significant (p less than 0.05) decrease in serum iron, no significant changes in complete blood count, serum electrolytes, renal and hepatic function tests, or serum C3 and C4 were noted. Although the trial was not designed to determine clinical efficacy, patients noted less morning stiffness, longer time to onset of fatigue, and improved global pain assessment (p less than 0.004); significant objective improvements were noted in joint pain, tenderness, swelling, and the number of affected joints (p less than 0.001). One-half of the treated patients had at least a 50 percent improvement in objective measures of antirheumatic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Identification and developmental expression of a chicken calsequestrin homolog

Calsequestrin (CAL) is a calcium-binding protein whose primary function is thought to involve sequestration of calcium in the muscle sarcoplasmic reticulum (SR). Little is known about the mechanisms regulating CAL expression, or about the role of this protein in muscle development. In addition, CAL may regulate calcium localization in some nonmuscle cells. We have identified an avian calsequestrin homolog. The predicted amino acid sequence of the avian CAL, first described as a laminin binding protein, and named aspartactin, is 70-80% identical to mammalian CAL sequences. We have used affinity-purified antibodies and cDNA probes to investigate expression in developing and adult chicken tissues. In adult chickens, the avian CAL homolog was expressed in slow and fast twitch skeletal muscle as well as in cardiac muscle. Surprisingly high levels of CAL protein were also detected in cerebellum. During development, CAL mRNA and protein were detected in Embryonic Day 5 (E-5) limb primordia, well before the initiation of myoblast fusion. In leg skeletal muscle, CAL protein and mRNA increase approximately 10-fold from E-8 to E-18 with a time course that just precedes myoblast fusion. This early expression pattern was also observed in cultured chicken pectoral myoblasts, and appears to be regulated at the level of mRNA abundance. The developmental profile of CAL expression is compared to that of other muscle proteins and possible additional functions of CAL are discussed.

Liver histology in patients receiving low dose pulse methotrexate for the treatment of rheumatoid arthritis

The liver histology of 52 patients treated with intermittent low dose pulse methotrexate for rheumatoid arthritis was evaluated using a modification of the Roenigk grading system. Patients studied had had an average of 3.2 years of treatment or had received 1.7 g methotrexate. No patient had cirrhosis; 15 (29%) patients had evidence of mild fibrosis. Histological abnormalities were not predicted by liver function test changes, with the exception that hypoalbuminaemia occurred in 60% of those with grade IV (modified criteria) findings. The need for liver biopsy in patients with rheumatoid arthritis treated with methotrexate before two years or 1500 mg of treatment has not been established. Whether serial liver biopsies will be needed beyond this time has yet to be determined.

Efficient transfection and expression of heterologous genes in PC12 cells

The PC12 pheochromocytoma cell line has been a favorite model system for cell and neurobiologists, but has proven relatively refractory to standard DNA transfection methods. We have found that the cationic lipid "lipofectin" provides a simple, gentle, and nontoxic procedure that vastly improves transfection efficiencies in PC12 cells. Transient expression of chloramphenicol acetyl transferase (CAT) driven by a Rous sarcoma virus long terminal repeat (LTR) is much more efficient using lipofectin when compared with calcium phosphate as a transfection procedure. Additionally, transient transfection of nerve growth factor (NGF)-differentiated PC12 cells proceeds with equal efficiency relative to naive, uninduced cells. Using the lipofectin procedure, the frequency of stable transfection is 100-fold higher than that reported with standard calcium phosphate precipitation protocols. To examine the effectiveness of different promoters for efficient expression of heterologous DNA in PC12 cells, three different promoter-bearing constructs were utilized. Each construct contains a different promoter sequence upstream from a chicken calsequestrin cDNA. A human cytomegalovirus (CMV) immediate early promoter construct produced the highest level of expression, followed by a human beta-actin promoter construct. Expression from a mouse Moloney sarcoma virus LTR construct could not be detected. These results overcome the previous transfection problems of low efficiency and low viability that have plagued many PC12 cell investigations.

Amyloidosis and Reiter's syndrome: report of a case and review of the literature

Reiter's syndrome is classically described as the triad of urethritis, conjunctivitis, and arthritis, It has many manifestations and has rarely been reported to occur in association with amyloidosis. Four cases of systemic amyloidosis have previously been reported. This case describes a patient who developed progressive renal amyloidosis after a 17-year history of severe Reiter's syndrome. Immunofluorescent staining of the renal biopsy was strongly positive for AA protein, the type of protein found in secondary amyloidosis. This is the first case in which amyloidosis has been proven to be secondary to Reiter's syndrome and not merely the coincidental occurrence of two rare diseases.

Acute, reversible hepatic failure associated with methotrexate treatment of rheumatoid arthritis

We describe 2 patients who developed reversible decompensated liver disease while taking pulse dosed methotrexate (MTX) for rheumatoid arthritis. One of the patients was available for biopsy and had chronic active hepatitis--a lesion not previously described with MTX. This appears to be a unique and unusual manifestation of MTX hepatotoxicity.

Regulation of nerve growth factor mRNA levels in developing rat heart ventricle is not altered by sympathectomy

The survival of sympathetic and sensory neurons is known to be controlled by nerve growth factor (NGF) supplied by the targets of innervation, yet little is known about how target NGF synthesis is regulated. We have investigated the pattern of NGF mRNA expression in developing rat heart ventricle using a sensitive RNA blotting procedure. We find that the concentration of NGF mRNA increases steadily from Embryonic Day 17 to peak levels at 10-14 days postnatal and then declines about twofold and stabilizes at the level found in adults. The rise in NGF mRNA concentration correlates with the arrival and differentiation of sympathetic nerve terminals in the heart and the cessation of sympathetic cell death. To assess the role of innervating sympathetic neurons in regulating NGF mRNA expression, neonatal rats were sympathectomized by treatment with 6-hydroxydopamine and heart ventricles were assayed for NGF message. Although this treatment reduced ventricle norepinephrine content by 82%, no significant change in NGF mRNA concentration was observed. These results suggest that the developmental program of NGF mRNA production in the heart is not influenced by innervating sympathetic neurons.

Methotrexate therapy in rheumatoid arthritis: 2-year retrospective followup study

Clinical and laboratory data in 124 patients with rheumatoid arthritis treated with methotrexate (MTX) were retrospectively reviewed over the initial 2 years after the start of treatment. Clinical improvement occurred in 103 (83%) patients after 12 weeks of treatment. At 2 years of followup, 60 patients (48%) continued to receive MTX with sustained clinical benefit. It has been discontinued in 64 (52%) patients (adverse drug reactions in 38, lack of clinical benefit in 15, and miscellaneous reasons in 11). Patients with adverse drug reactions had higher initial serum creatinine and blood urea nitrogen values than patients without adverse drug reactions.

Hepatic ultrastructure after methotrexate therapy for rheumatoid arthritis

Twenty-six patients receiving long-term oral methotrexate (MTX) therapy for rheumatoid arthritis (24 patients) or psoriasis (2 patients) were prospectively evaluated for alterations in liver morphology by light microscopy, electron microscopy, and immunofluorescence microscopy. Although only 4 MTX-treated patients had light microscopic evidence of mild fibrosis, all had evidence of collagen deposition in the space of Disse near Ito cells and changes in hepatocyte lysosomes on electron microscopy. These findings were absent from control livers. Fibrinogen, fibronectin, and type IV collagen were identified by immunofluorescence in both MTX-treated patients and controls. We conclude that long-term MTX therapy for rheumatoid arthritis is associated with alterations in hepatic ultrastructure, including collagen deposition in the space of Disse and changes in hepatocyte lysosomes.

Amino acid sequence and distribution of mRNA encoding a major skeletal muscle laminin binding protein: an extracellular matrix-associated protein with an unusual COOH-terminal polyaspartate domain

Two cDNAs encoding an abundant chicken muscle extracellular matrix (ECM)-associated laminin-binding protein (LBP) have been isolated and sequenced. The predicted primary amino acid sequence includes a probable signal peptide and a site for N-linked glycosylation, but lacks a hydrophobic segment long enough to span the membrane. The COOH terminus consists of an unusual repeat of 33 consecutive aspartate residues. Comparison with other sequences indicates that this protein is different from previously described LBPs and ECM receptors. RNA blot analysis of LBP gene expression showed that LBP mRNA was abundant in skeletal and heart muscle, but barely detectable in other tissues. Blots of chicken genomic DNA suggest that a single gene encodes this LBP. The amino acid sequence and mRNA distribution are consistent with the biochemical characterization described by Hall and co-workers (Hall, D. E., K. A. Frazer, B. C. Hahn, and L. F. Reichardt. 1988. J. Cell Biol. 107:687-697). These analyses indicate that LBP is an abundant ECM-associated muscle protein with an unusually high negative charge that interacts with both membranes and laminin, and has properties of a peripheral, not integral membrane protein. Taken together, our studies show that muscle LBP is a secreted, peripheral membrane protein with an unusual polyaspartate domain. Its laminin and membrane binding properties suggest that it may help mediate muscle cell interactions with the extracellular matrix. We propose the name "aspartactin" for this LBP.

A controlled trial comparing sulfasalazine, gold sodium thiomalate, and placebo in rheumatoid arthritis

One hundred eight-six patients with active rheumatoid arthritis were evaluated in a double-blind, randomized study that compared treatment with sulfasalazine (SSZ) (2 mg/day), gold sodium thiomalate (GST) (50 mg/week), and placebo (PBO). The 37-week course of therapy was completed by 109 patients. While marked improvement was seen in all 3 treatment groups, the only statistically significant differences between SSZ or GST and PBO were in a decreased erythrocyte sedimentation rate and increased grip strength in the right hand. GST is known to be superior to PBO, and the response of the GST-treated group was similar to that seen in other trials. The response of the PBO group, however, was much greater than in other placebo groups we have studied. SSZ was similar in efficacy to injectable gold, but was better tolerated. Because of adverse drug reactions (most commonly, rash, stomatitis, and proteinuria), 41% of patients were withdrawn from the GST treatment. Untoward drug effects (most frequently, rash and gastrointestinal distress) caused 16% of patients to be withdrawn from SSZ therapy.

One-year experience in patients treated with auranofin following completion of a parallel, controlled trial comparing auranofin, gold sodium thiomalate, and placebo

Following a 21-week double-blind trial that compared the effects of treatment with auranofin (AUR), gold sodium thiomalate, and placebo in 193 patients, 147 patients entered a 1-year, open-label study of treatment with AUR (6 mg/day). Results of this open-label study suggest that AUR has a long-term use profile similar to that of other slow-acting antirheumatic drugs. AUR appears to be capable of sustaining an initial response to gold sodium thiomalate. The withdrawal rate remains relatively high: Nearly half of the study patients had discontinued AUR by the end of 1 year.

Low dose pulse methotrexate in rheumatoid arthritis: an 8-year experience with hepatotoxicity

The clinical utility of standard liver function tests for monitoring low dose pulse methotrexate therapy is reviewed in 163 rheumatoid arthritis patients over an eight-year period. Abnormalities of hepatic enzymes were seen in 58% of patients but led to cessation of therapy in only 5%. Moderate alcohol intake did not affect the frequency of liver test abnormalities. Abnormalities were seen more frequently in patients with longer duration of methotrexate therapy and in those with higher total dose. There was no correlation between liver test abnormalities and day of serum sampling relative to day of methotrexate dosing, nor was a correlation seen between liver test abnormalities and total weekly dose of methotrexate. Methotrexate has been demonstrated to be an effective drug in the treatment of rheumatoid arthritis. The clinical utility of standard liver tests to predict the potential for hepatotoxicity is questionable.

Slow-acting anti-rheumatic drug therapy for rheumatoid arthritis

Rheumatoid arthritis is a disorder that frequently can be controlled with a program of physical therapy, rest and therapeutic doses of aspirin or another nonsteroidal anti-inflammatory medication. However, some patients' diseases are not controlled on this regimen. These patients are candidates for therapy with slow-acting anti-rheumatic drugs. This article discusses the indications for use of these medications as well as the potential benefits and adverse drug reactions commonly associated with their use.

Hematuria in patients with rheumatoid arthritis receiving gold and D-penicillamine

We reviewed the urinalyses from 2 multicenter controlled randomized trials, one comparing moderate and low dose D-penicillamine to placebo and another comparing gold sodium thiomalate (GSTM), auranofin (AF) and placebo. In the D-penicillamine trial 30% of the 40 patients taking placebo, 34% of the 70 patients receiving 125 mg/day of D-penicillamine and 31% of the 61 patients receiving 500 mg of D-penicillamine had recurrent hematuria. In the GSTM/AF trial, 35% of the 43 placebo treated patients, 35% of the 54 GSTM treated patients and 30% of the 64 AF treated patients had hematuria. No significant difference in the frequency of hematuria between the groups in either trial was apparent. These findings suggest that the traditionally held belief that gold and D-penicillamine cause hematuria should be reconsidered.

Pulmonary disease during the treatment of rheumatoid arthritis with low dose pulse methotrexate

Methotrexate therapy has been effective in the treatment of RA with short term experience suggesting little serious adverse reactions. Our review of 168 patients receiving methotrexate has identified nine patients with probable or possible methotrexate-induced pulmonary toxicity, giving a prevalence of 5% and an incidence of 3.9 per 100 patients per year. No clinical or laboratory features showed an association that could potentially predict the development of pulmonary disease. All patients experienced complete recovery with supportive care and/or corticosteroid therapy. Clinical monitoring for this complication is warranted in all patients receiving long term methotrexate therapy for RA.

Lack of association between HLA-DR2 and clinical response to methotrexate in patients with rheumatoid arthritis

Recent studies have indicated an association between the HLA-DR2 phenotype and substantial response to methrotrexate in patients with rheumatoid arthritis (RA). To further resolve this issue, we analyzed this relationship. Our data, obtained from a multicenter, double-blind study of rigorously assessed patients with RA, demonstrated that neither HLA-DR2 nor any other HLA-DR specificity is significantly associated with a substantial clinical response to methotrexate in patients with RA.

Diagnostic criteria in rheumatoid arthritis

For rheumatoid arthritis (RA), criteria have been developed for classification of groups of patients in population surveys, selection for therapeutic trials, inter-institutional comparison of patients, evaluation of diagnostic trials, diagnosis of RA in individual patients, estimation of disease frequency, and assistance in determining prognosis. The American Rheumatism Association (ARA) "Criteria for the Classification of Rheumatoid Arthritis-Diagnostic Criteria for Rheumatoid Arthritis" were published in 1958 and have become a standard. These criteria are empiric and attempt to incorporate reasonable combinations of sensitivity and specificity. Despite the recognition that these criteria should be expected to change with improved knowledge, no further modification has been published. Other criteria such as the ARA "Proposed Criteria for Rheumatoid Arthritis" represent an important effort to encourage uniformity in definitions and use of the term remission. Yet it is well to remember that they have never been tested in prospective studies and are considered preliminary. The Co-operative Systematic Studies in Rheumatic Diseases, when studying slow-acting anti-rheumatic drugs, have chosen to use clinical endpoints such as 50% improvement in joint tenderness and swelling counts (or scores) rather than combined variables which include morning stiffness and changes in laboratory variables. This approach permits the true assessment of drug effects. In summary, current criteria have served us well. Nonetheless, we should not become complacent and should always question their sensitivity, specificity and application.

Nerve growth factor gene expression in the developing rat brain

The regulation of nerve growth factor (NGF) protein and NGF messenger RNA (mRNA) in the developing rat brain has been studied to assess the hypothesis that NGF supports the differentiation of cholinergic neurons in the basal forebrain. In the adult, the major targets of these neurons, the hippocampus and neocortex, contain the highest concentrations of NGF mRNA, but comparatively low ratios of NGF protein to its mRNA. In contrast, a high concentration of NGF protein and a low concentration of NGF mRNA were seen in the basal forebrain, consistent with retrograde transport of NGF protein into this region from the neocortex and hippocampus. In these two target regions NGF and NGF mRNA were barely detectable at birth, their concentrations increased to a peak at day 21, and then NGF mRNA, but not NGF protein, declined threefold by day 35. NGF accumulation in the basal forebrain paralleled that in the target regions and preceded an increase in choline acetyltransferase, suggesting that the differentiation of cholinergic projection neurons is indeed regulated by retrogradely transported NGF. In addition, high ratios of NGF protein to NGF mRNA, comparable to that in the basal forebrain, were seen in the olfactory bulb and cerebellum, suggesting that NGF may be transported into these regions by unidentified neurons.

Circulating HLA-DR bearing T cells: correlation with genetic rather than clinical variables

Elevated levels of circulating HLA-DR bearing (activated) T cells have been reported in a variety of conditions. The role played by these cells in the pathogenesis of disease is not established. We found elevated levels of activated T lymphocytes in patients with rheumatoid arthritis (RA), dermatitis herpetiformis, gluten sensitive enteropathy, as well as presumed healthy persons with HLA-B8 antigen. We could not show any change in the concentration of these cells with disease activity, therapy, or in a case of dermatitis herpetiformis, challenge with the presumed antigen, gluten. Our studies do not suggest an apparent causal relationship between activated T lymphocytes and the above disorders.

Methotrexate and the liver

The findings of liver studies in 29 patients who were treated with low dose pulse methotrexate for rheumatoid arthritis (RA) are described. The biopsy specimens of 22 patients (76%) showed liver abnormalities, but cirrhosis did not develop in any patient. There were no statistically significant differences in age, duration of treatment, or cumulative dose between patients in whom abnormal liver histology developed and those in whom it did not. Our findings showed that isolated elevations of the aminotransferase enzymes or alkaline phosphatase levels did not predict liver disease, nor did the absence of elevation of these enzymes assure the absence of liver disease. Serial elevations of the aminotransferase and/or alkaline phosphatase enzyme levels and the development of hypoalbuminemia during treatment were specific indicators of the development of liver disease. In the patients studied, significant liver disease did not develop before 2 years of therapy or with a cumulative dose of methotrexate of less than 1500 mg.

Chlorambucil therapy in rheumatoid arthritis: clinical experience in 28 patients and literature review

Our clinical experience in 28 patients receiving chlorambucil for rheumatoid arthritis (RA) and the reports on chlorambucil therapy are reviewed. Our study population and other reports generally represent patients with severe RA who had either failed to improve or developed significant toxicity during previous treatment with conventional slow acting anti-rheumatic drugs (SAARDs). Seventy-two percent of patients had a significant clinical improvement during chlorambucil therapy and reports of complete remission are given, although the incidence of remission is unknown. Hematologic complications are often reported, but appeared more frequently in our experience than previously reported. Hematologic toxicity required that chlorambucil be discontinued in the majority of our cases. Two deaths from suspected drug induced malignancies are reported. Although chlorambucil appears to be effective in the control of active RA, the potential for drug induced toxicity and malignancies may outweigh the benefit of continued use of this experimental therapy in RA.

Erosive arthritis in a patient with amyloid arthropathy

Amyloid arthropathy is said to be distinguished roentgenographically from rheumatoid arthritis by the absence of joint space narrowing and the absence of articular erosions. We present a patient with multiple myeloma with swelling, stiffness and firm synovial thickening of the wrists, metacarpophalangeal joints and proximal interphalangeal joints whose hand radiographs showed articular erosions of the carpal joints and ulnar styloid and joint space narrowing of the proximal interphalangeal joints and metacarpophalangeal joints. Synovial biopsy of the left wrist showed amyloid deposits with no inflammation. Previous reports of X-ray changes in amyloid arthropathy note preservation of joint spaces or widening. Erosions when noted are of non-articular bone rather than of the articular surface. This is the first case report of erosive articular disease in amyloid arthropathy.

Circulating immune complexes containing secretory IgA in jejunoileal bypass disease

Thirteen patients were studied after jejunoileal bypass (JIB) surgery. Seven developed arthritis and six did not. Circulating immune complexes containing IgG and IgA were detected in the sera of patients with and without arthritis. IgA complexes were shown to contain secretory component, a protein predominantly associated with intraluminal IgA, in significantly higher levels in patients with arthritis. Analytical ultracentrifugation showed complexes of approximately 10 X 8S, consistent with the size of secretory IgA. Arthritis after JIB appears to be associated with circulating immune complexes containing secretory IgA.

Characterization of T cells bearing HLA-DR antigens in rheumatoid arthritis

It has been demonstrated that T cells bearing HLA-DR antigens on their surface are actively involved in an immune response. In diseases of disordered immunoregulation, including rheumatoid arthritis (RA), there are elevated numbers of circulating HLA-DR+ T cells. In this study, we examined the cellular physiology of these T cells in RA patients. Using tritiated thymidine incorporation, we found that, in most patients, HLA-DR+ cells do not account for a significant amount of spontaneous proliferation found in peripheral blood T cells. RNA hybridization studies, using a cloned HLA-DR alpha chain gene probe, indicate that the T cells actively synthesize HLA-DR antigens rather than passively adsorbing them. The cell surface phenotype of the HLA-DR+ T cells was analyzed using double immunofluorescence and a variety of monoclonal antibodies. The expression of T cell differentiation antigens T4, T6, T8, and T10 varied markedly from patient to patient. In some patients, a significant number of cells expressed both T4 and T8 antigens. Most HLA-DR+ cells also express antigens defined by the following antibodies: anti-Tac (the interleukin-2 receptor), J2 (a glycoprotein found on T cell blasts), and ILR-1 (a class II major histocompatibility complex antigen). Activated T cells bearing HLA-DR antigens may play a role in the development of RA. Our data demonstrate that although these cells are not lymphoblasts, they possess a distinct cell surface phenotype.

The role of a signaling protein in bacterial sensing: behavioral effects of increased gene expression

A recombinant DNA approach has been used to study intracellular signaling in the bacterial sensing system. The Escherichia coli cheY gene, whose function is unknown, has been subcloned behind the synthetic inducible tac promoter. The resulting plasmid directs the synthesis of the Y protein in response to isopropyl beta-D-thiogalactoside, independent of its usual operon control. When this construct was introduced into wild-type and mutant cells, the Y protein caused a clockwise rotational bias in the flagellar motors. This effect was observed even in heavily biased counterclockwise strains lacking most of the central chemotaxis processing genes. The results show that the Y protein has a direct influence on flagellar rotation not requiring other processing genes of the sensing system. The Y protein appears to bind directly to a part of the flagellar motor, probably the flaA gene product, and it is probably the key element in biasing the motor toward the clockwise rotational direction.

Susceptibility and resistance to 6-sulfanilamidoindazole-induced arthritis among inbred strains of rats

Inflammation induced by 6- sulfanilamidoindazole (6-SAI) in aged, outbred rats is predictably produced, but the pathogenesis is not understood. We demonstrate the variable resistance of 15 inbred rat strains to 6-SAI arthritis. Susceptibility to 6-SAI arthritis is not directly linked to the major histocompatibility complex, although resistance is related to the major histocompatibility complex in other experimental forms of rat arthritis. The genetic background of these inbred rat strains appears to have a major role in 6-SAI arthritis susceptibility.

Tandem duplication and multiple functions of a receptor gene in bacterial chemotaxis

The aspartate receptor in bacterial sensing, previously identified with the tar gene, has been shown to be duplicated in tandem in Escherichia coli. Each gene, which we refer to as tar and tap, respectively, codes for a 60,000-dalton protein. By genetic engineering experiments in which each gene is introduced separately into E. coli strains, it is shown that each transmembrane receptor can respond to the small molecule aspartate, to the maltose-protein-chemoeffector complex, and to repellents.

Molecular cloning and amplification of the adenylate cyclase gene

A segment of DNA containing cya, the gene for adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1], has been isolated from Salmonella typhimurium. The phage lambda gt4 was used as a cloning vector and adenylate cyclase-positive hybrid phages were isolated that complemented adenylate cyclase-negative bacteria. The cloned DNA fragment encodes a polypeptide of molecular weight 81,000 that gives rise to adenylate cyclase activity. This protein represents a functional mutant of the bacterial adenylate cyclase. When the cya gene was amplified by inserting into a multicopy plasmid, the enzyme activity was overproduced 20-fold, but the cyclic AMP level increased only 60%, suggesting several probable regulatory mechanisms. Overproduction of enzymes by recombinant DNA techniques can be a useful probe of relationships in the metabolizing organism in vivo.

Articular complications of jejunoileal bypass surgery

Articular complications are now frequently recognized with jejunoileal-bypass surgery for morbid obesity. We have evaluated 6 referred patients with these problems and 50 consecutive patients who had this procedure. The arthritis is variable but usually affects multiple joints. Four patients were seen during acute attacks of arthritis and all had cryoprecipitable material in their sera and plasma. Three of these 4 patients had evidence of Group D streptococcal antigen present while their joint disease was active, suggesting a possible role for bacterial antigens in the pathogenesis of the arthritis of jejunoileal bypass.