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ID PMID Title PublicationDate abstract
8398607 Murine models of autoimmune disease and Sjögren's syndrome. 1993 Sep Murine models of autoimmune disease exhibit heterogenous features that are now being understood in terms of their basic molecular defects. Defects in apoptosis genes or genes that contribute to B-cell activation, T-cell tolerance loss, and development of autoimmune disease, including glomerulonephritis, have been identified. The interaction of primary and secondary predisposing genes leads to a diverse spectrum of autoimmune features that is different in different strains of mice. The challenge in the future will be to correlate these primary and secondary autoimmune genes with specific environmental triggers to explain the diverse spectrum of autoimmune disease. The ability to correct the apoptosis defect and autoimmune disease in CD2-Fas transgenic MRL-lpr/lpr mice brings hope that genetic therapy will eventually be possible in humans.
8461923 Patients with anticentromere antibodies, clinical features, diagnoses and evolution. 1993 Apr The sera of 1373 patients derived from a random population of 2627 individuals examined in a rheumatology outpatient clinic were found to be positive for antinuclear antibodies (ANA). Forty-seven of 1373 ANA positive patients (3.42%) presented a pattern of anticentromere antibodies (ACA), and of these 41 were followed-up. The predominant clinical features among ACA positive patients were Raynaud's phenomenon, arthralgias, scleroderma affecting the hands, feet, face and forearms, telangiectases and pulmonary involvement. There were 26 patients (64%) with limited cutaneous systemic sclerosis (lSSc), seven with primary Sjögren's syndrome (Ss) (17%), five with idiopathic Raynaud's phenomenon (IRPh) (12%) and three (7%) with other diseases. The lSSc subset was characterized by a significantly younger age for disease onset than for the IRPh patients. The Raynaud's phenomenon of lSSc patients lasted for many years before the onset of scleroderma, while their pulmonary involvement was mild and subclinical. The Ss patients with ACA were characterized by a lower incidence of parotid gland enlargement and anti-La (SSB) antibodies than described in the literature. Finally, the presence of ACA correlates with the clinical criteria proposed for the diagnosis of lSSc.
1531348 T cell receptor repertoire of infiltrating T cells in lips of Sjögren's syndrome patients 1992 Feb Infiltrating T cells around salivary glands in the lips of Sjögren's syndrome (SjS) patients are crucial in the pathogenesis of this disease. To analyze the nature of infiltrating T cells, their T cell receptor repertoire was examined with quantitative polymerase chain reaction. The repertoire of V beta transcripts in lips of SjS was not restricted; however, the V beta 2 and V beta 13 genes were predominantly expressed on the T cells of lip specimens in six and four of seven lips, respectively. Predominance of these genes was specific in lips because no predominant V beta transcripts were found in lips from healthy subjects and PBLs from SjS patients. These results indicated that the V beta 2- and V beta 13-positive T cells expanded specifically and preferentially in SjS lips, thereby suggesting the possible role in triggering the autoimmunity of this disease.
9099920 The expression of human endogenous retrovirus-3 in fetal cardiac tissue and antibodies in 1996 Jun Endogenous retrovirus-3 (ERV-3) is an endogenous retrovirus encoding an open reading frame for an envelope protein expressed in placenta. In this study we also found high levels of expression in fetal heart, with peak expression occurring between 11 and 17 weeks of gestation. Antibodies to a peptide corresponding to a predicted epitope of ERV-3 were studied by ELISA in sera from 32 healthy women, 47 women during pregnancy, 19 post-partum, 34 with Sjogren's syndrome (SS), 28 with systemic lupus erythematosus (SLE) and 48 mothers of babies with congenital heart block (CHB). Elevated levels of antibodies to ERV-3 were found in normal pregnancy and in patients with SS or SLE. Compared with normal sera the highest levels occurred in mothers of CHB babies (P < 0.001). Antibodies from sera from three CHB mothers bound to recombinant transmembrane protein of ERV-3 on immunoblots, and to sections of fetal cardiac tissue and placenta. This study has shown evidence of autoimmunization to ERV-3 during pregnancy, with particularly high levels of antibodies in mothers of CHB babies. The expression of ERV-3 in fetal heart and the presence of antibodies in maternal sera suggest a possible role in the pathogenesis of CHB.
8721452 Sjögren's syndrome plasma cell panniculitis and hidradenitis. 1996 Apr We present a 42-year-old woman with primary Sjögren's syndrome and a polyclonal gammopathy who presented with pretibial petechiae, purpura, and tender indurated plaques. The indurated plaques revealed a lobular plasma cell panniculitis, and thus Sjögren's syndrome should be added to the short list of collagen vascular diseases that can present as plasma cell panniculitis. Her biopsies also demonstrated intense perieccrine plasma cell infiltrates that may account for Sjögren's syndrome-associated hypohidrosis. We also observed occasional vascular occlusion of vessels with an amorphous, eosinophilic material possibly related to her hypergammaglobulinemic purpura.
7993711 Neonatal lupus syndromes. 1994 Sep Neonatal lupus continues to generate considerable interest despite its rarity; more than 15 original contributions were made to the literature in the past year. Diverse aspects of this "syndrome" of passively acquired autoimmunity have been covered. Experiments using a rabbit model provided insights into the pathogenicity of maternal anti-Ro/SS-A and anti-La/SS-B antibodies. Perfusion of rabbit hearts with anti-Ro/SS-A and anti-La/SS-B sera resulted in conduction abnormalities in whole adult rabbit hearts and induced a reduction in the peak slow inward current in patch-clamp experiments of isolated rabbit ventricular myocytes, suggesting involvement of calcium channels. Clinical investigations are moving away from case reports, and recent studies now include substantial entries. Assuming that patients reported from the United States, Finland, and England are all separate, sera from at least 100 different mothers of infants with congenital heart block have been studied. Although there is apparently no serologic profile that is unique to mothers of affected children, compared with mothers of healthy children, anti-Ro/SS-A antibodies (anti-52-kD antibodies are more prevalent by immunoblot in congenital heart block, although all these sera are likely to have anti-60-kD antibodies by immunoprecipitation) are usually of high titer and associated with anti-La/SS-B antibodies. To date, the only maternal autoantibodies that have been associated with congenital heart block recognize Ro/SS-A or La/SS-B antigens. Mothers of affected infants are often asymptomatic, and when symptomatic, the clinical features are frequently characteristic of Sjögren's syndrome. Although treatment of affected fetuses with dexamethasone has successfully diminished associated effusions, there has been no report of reversal of established third-degree heart block.
7959226 Coeliac disease--associated disorders and survival. 1994 Sep The associated diseases in 335 coeliac patients diagnosed 1980-90 were compared with age and sex matched control patients with various gastrointestinal symptoms. Endocrine disorders were found in 11.9% of coeliac and 4.3% of control patients (p = 0.0003). Coeliac patients had insulin dependent diabetes mellitus significantly (p = 0.0094) more often (5.4%) than control patients (1.5%). connective tissue diseases were found in 7.2% of coeliac and in 2.7% of control patients (p = 0.011). Sjögren's syndrome occurred in 3.3% of coeliac patients and in 0.3% of controls (p = 0.0059). Autoimmune thyroid diseases were found in 5.4% and asthma in 3.6% of coeliac patients, but also in 2.7% and 3.6%, respectively, among control patients. The incidences of malignant diseases and the survival rate in coeliac patients were compared with those in the Finnish population. Ten coeliac patients developed a cancer during the follow up (mean 5.3 years, range 1-12) but none had a lymphoma. The risk of malignant diseases in coeliac patients did not differ from that in the Finnish population in general. Eleven coeliac patients died during the follow up. The five year survival rates of coeliac patients did not differ from those in the general population. At least 83% of the coeliac patients adhered strictly to the gluten free diet, which may explain the favourable outcome.
8423383 Anti-Ro(SS-A) HLA-DR3-positive women: the interrelationship between some ANA negative, SS, 1993 Jan During the past 15 years, the clinical spectrum associated with the anti-Ro(SS-A) antibody response has been defined. Various clinical presentations, including subacute cutaneous lupus erythematosus, the neonatal lupus syndrome, the Sjögren's syndrome/lupus erythematous overlap syndrome, and primary Sjögren's syndrome, have been detected in association with the anti-Ro(SS-A) response. The anti-Ro(SS-A) antibody response is associated with the HLA-DR2 and HLA-DR3 phenotypes. There is now a good deal of evidence to suggest that many anti-Ro(SS-A)-positive HLA-DR3 women are genetically closely related, sharing in common an enriched frequency of the HLA-DR3-linked B8, DQw2, and DRW52 phenotypes. DNA sequence studies have confirmed this genetic relationship. These studies have led us to the following conclusions. 1) The HLA-DR2 and HLA-DR3 associations with systemic lupus erythematosus and the HLA-DR3 association with Sjögren's syndrome are related to the anti-Ro(SS-A) antibody response and not to the clinical disease expression. 2) HLA-DR3 anti Ro-positive female patients with first-degree Sjögren's syndrome, subacute cutaneous lupus erythematosus, or Sjögren's syndrome, or who are asymptomatic, are immunogenetically closely related even though the clinical presentations are strikingly different. All these HLA-DR3 anti-Ro(SS-A) antibody-positive women are at risk to give birth to a child with the neonatal lupus syndrome.
8628840 Articulatory speech performance in patients with salivary gland dysfunction: a pilot study 1995 Nov Difficulty with speech is a common complaint of patients with xerostomia resulting from salivary gland dysfunction. The purpose of this pilot study was to assess and compare speech tasks in three patient groups with salivary gland dysfunction arising from different etiologies (primary Sjogren's syndrome, secondary Sjogren's syndrome with systemic lupus erythematosus, and irradiation therapy for head and neck cancer) and a matched control group. Diadochokinetic speech tasks were quantified clinically and videofluoroscopically. The results indicated that significantly fewer speech tasks were completed, with or without water, by the groups with salivary gland dysfunction than by the control group. Videofluoroscopy provided excellent quantitative analysis, yielding results similar to those of the clinical measurement. In a subjective self-assessment, subjects with salivary gland dysfunction reported more problems with speech than did control subjects.
8544385 [Pulmonary non-Hodgkin's lymphoma that arose in mucosa-associated lymphoid tissue of the s 1995 Oct A 70-year-old woman complained of a dry mouth and swelling in the area of the left parotid gland for 6 years, and was admitted for evaluation of an abnormal shadow on chest X-ray film. She underwent a lip biopsy and a 99mTcO4- scintigram of the salivary gland, and Sjögren's syndrome was diagnosed. Histopathological examination of the percutaneous lung biopsy specimen showed pseudolymphoma, and examination of a specimen of the left parotid gland tumor showed myoepithelial sialadenitis. The patient died of respiratory failure due to a right pleural effusion 4 years later. Autopsy revealed pulmonary non-Hodgkin's lymphoma (diffuse, large, B cell, IgG) with monotonous infiltration of centrocyte-like cells. A retrospectively resected specimen of the left parotid gland tumor showed non-Hodgkin's lymphoma similar to that found in the autopsied lung. This patient probably had pulmonary non-Hodgkin's lymphoma that arose in mucosa-associated lymphoid tissue of the salivary gland and was associated with Sjögren's syndrome.
8178848 Fetal cardiovascular hemodynamics in the presence of complete atrioventricular block. 1994 May OBJECTIVE: Our purpose was to follow serially the hemodynamic adaptation to a congenital complete heart block in a human fetus. STUDY DESIGN: Longitudinal and serial M-mode and Doppler echocardiography over a 10-week span were performed on a fetus affected by complete heart block. Ventricular fractional shortening, size, and flow across the atrioventricualr valves and outflow tracts were determined starting at 20 weeks up to the time of delivery. Neonatal Doppler follow-up was performed at 2 days of life after implantation of a temporary pacemaker. RESULTS: The right and left ventricles were able to adapt to sustained bradycardia by increasing their size. This ventricular dilatation was also associated with an increase in fractional shortening, which was associated with ventricualr free wall hypertrophy. When ventricualr heart rate decreased to 38 beats/min, fractional shortening decreased, this was associated with the rapid onset of ascites and pericardial effusion. CONCLUSION: In the presence of sustained bradycardia ventricular output can increase, because this fetus was able to increase ventricular size and fractional shortening and wall thickness.
8895006 Side effects of high-dose interferon therapy for chronic hepatitis C. 1996 Sep BACKGROUND/AIMS: Various side effects have been reported in patients treated with alpha interferon, but their incidence and prognosis remain unknown. METHODS: Nine hundred and eighty-seven patients with chronic active hepatitis C received 6 to 10 MU of alpha interferon per day for 2 weeks and 3 times per week for 22 weeks. Autoantibodies, thyroid function tests, and fasting plasma glucose concentrations were evaluated prior to alpha interferon therapy. RESULTS: Of the 987 patients, 310 were required reduction in the dose of alpha interferon to 3 MU/day or cessation of alpha interferon therapy because of adverse reactions such as flu-like symptoms, leukopenia, and thrombocytopenia. Of the remaining 677, five developed diabetes mellitus, 12 had hyperthyroidism, and six acquired hypothyroidism. Of the 18 with thyroid disorders, five demonstrated antimicrosomal antibodies before therapy. Forty-four patients revealed high or low concentrations of thyroid stimulating hormone at the end of alpha interferon therapy. Three patients developed interstitial pneumonia, one acquired systemic lupus erythematosus-like syndrome, two had autoimmune hepatitis, two developed rheumatoid arthritis, and one developed autoimmune thrombocytopenic purpura. No patients had a history of an autoimmune disorder. One patient experienced sudden hearing impairment and one had retinal detachment. Melena was seen in three patients; two of these cases were compatible with ischemic colitis. Symptoms of depression were seen in 23 patients, and one patient manifested memory loss. CONCLUSION: High-dose alpha interferon therapy induces various adverse effects. Most of the side effects cannot be predicted, but are reversible.
8619771 Referral patterns of uveitis in a tertiary eye care center. 1996 May OBJECTIVE: To analyze the referral patterns and diagnosis of uveitis during the past decade in a large tertiary eye center. DESIGN: The records of 1237 patients with uveitis referred to the Immunology Service of the Massachusetts Eye and Ear Infirmary from 1982 to 1992 were classified and analyzed. Data regarding sex, race, nationality, referral site, ages at presentation and onset of uveitis, ocular involvement, clinical characteristics, ocular condition, and systemic disease associations were obtained. RESULTS: The mean age at onset of uveitis was 37.2 years; the male-to-female ratio was 1:1.4. Most patients were white (85.8%), born in the United States (83.1%), and referred from within New England (84.7%). Anterior uveitis was most common (51.6%), followed by posterior uveitis (19.4%), panuveitis (16.0%), and intermediate uveitis (13.0%). Chronic (58.3%), nongranulomatous (77.7%), and noninfectious (83.1%) were the most frequent types of uveitis. The most common entities included idiopathic (34.9%), seronegative spondyloarthropathies (10.4%), sarcoidosis (9.6%), juvenile rheumatoid arthritis (5.6%), systemic lupus erythematosus (4.8%), Behçet's disease (2.5%), and the acquired immunodeficiency syndrome (2.4%). CONCLUSION: The appearance of new uveitic entities, such as the acute retinal necrosis syndrome, multifocal choroiditis and panuveitis, birdshot retinochoroidopathy, and acquired immunodeficiency syndrome-related uveitis, and the reemergence of the classic infectious causes of uveitis, tuberculosis and syphilis, have changed the way we approach the diagnosis and management of posterior and panuveitis at the Massachusetts Eye and Ear Infirmary.
8752520 [Expression of bc1-2 protein in collagen vascular diseases with pulmonary interstitial inv 1995 Dec Expression of bc1-2 protein was studied immunohistochemically in 25 patients with collagen vascular diseases and in 10 patients with idiopathic interstitial pneumonia. The collagen vascular diseases included rheumatoid arthritis (n = 9), progressive systemic sclerosis (n = 9), polymyositis/dermatomyositis (n = 4), Sjögren's syndrome (n = 2), and systemic lupus erythematosus (n = 1). All 35 patients underwent open lung biopsy; cellular infiltration, fibrosis, and lymphoid aggregation were scored according to Cherniack's classification. T lymphocytes (CD43: DFT-1) and B lymphocytes (CD20:L-26) were also evaluated. Expression of bc1-2 protein was dominant in T lymphocytes infiltrating the alveolar interstitium and in B lymphocytes in the mantle zone of lymphoid follicles. In collagen vascular diseases, the degree of expression of bc1-2 protein in those T lymphocytes was closely related to the alveolar lymphocyte infiltration score. However, these findings were not marked in the patients with idiopathic interstitial pneumonia, and were not related to the underlying disease in the patients with collagen vascular diseases. The expression of bc1-2 protein in T lymphocytes was not related to fibrosis or to lymphoid aggregation. Expression of bc1-2 protein in B lymphocytes did not correlate with pathological scores or with underlying disease. Bc1-2 protein has been recognized as an oncogene that suppresses apoptosis. Marked expression of bc1-2 protein in T lymphocytes from patients with collagen vascular diseases indicates that oversuppression of apoptosis may be related to the pathogenesis of pulmonary interstitial involvement in these conditions. Further clinicopathological studies focusing on apoptosis in collagen vascular diseases and in idiopathic interstitial pneumonia are needed.
8835249 A genetic approach to the aetiology of giant cell arteritis: depletion of the CD8+ T-lymph 1995 Nov OBJECTIVE: To investigate the CD8+ T-cell concentrations in first degree relatives of patients with giant cell arteritis (GCA) in order to evaluate whether the low CD8+ T-cell values found in most patients with GCA are acquired or hereditary. METHODS: Probands were 5 patients with arteritis temporalis (TA) and 15 with polymyalgia rheumatica (PMR). Forty of 60 available relatives participated in the study. They were all interviewed concerning signs of previous illness. A blood sample screening was performed, including IgM-RF and ANA on Hep-2 cells. Age- and sex-matched controls consisted of 29 persons with no history of inflammatory or malignant diseases. Measurements of the T-lymphocyte subsets CD3+, CD4+ and CD8+ were made after Ficoll-Hypaque separation. RESULTS: Healthy relatives disclosed a significantly decreased CD8+ percentage in their peripheral blood compared with controls. The median CD8+% in relatives was 17% (C1 95% 15-20%) and in controls it was 23% (C1 95% 20-28%). Twelve relatives had a decreased concentration of CD8+ T-cells and 10 showed an elevated CD4+/CD8+ ratio. Two relatives had GCA and 3 had rheumatoid arthritis (RA). In one family 3 healthy siblings participated and showed extremely low CD8+ percentages (2.5%, 6.5%, 3.4%) and absolute values (0.042, 0.102, 0.035 x 10(9)/l) CONCLUSION: TA, PMR and RA are frequently (12.5%) found in the first degree relatives of patients with GCA. The finding of extremely low CD8+ T-cell values in completely healthy relatives indicates that the CD8+ T-cell depletion seen in patients with GCA is a hereditary characteristic.
7473131 The immunosuppressant leflunomide inhibits lymphocyte proliferation by inhibiting pyrimidi 1995 Nov Leflunomide is a novel immunosuppressive compound that is effective in the treatment of animal models of autoimmune disease and human rheumatoid arthritis. The mechanism of action is unknown. Here we show that leflunomide blocked 1) increases in nucleolar size and number, 2) upregulation of the nuclear protein antigens (PCNA and Ki-67), 3) increases in uridine incorporation and total RNA and DNA content, 4) cell cycle progression and 5) proliferation in mitogen-stimulated rat spleen mononuclear cells and human peripheral blood mononuclear cells (HPBMC). Exogenous uridine reversed the leflunomide-dependent inhibition of the normal increase in total RNA and DNA content in mitogen-stimulated HPBMC and rat spleen cells. Uridine reversed the leflunomide-dependent inhibition of cell cycle progression in stimulated rat cell cultures. Either uridine or cytidine, which can be converted to uridine by cytidine deaminase, reversed the antiproliferative effect of leflunomide in HPBMC. Dihydroorotate accumulated in leflunomide-treated human T-lymphoblastoid cells, suggesting that the compound inhibited the fourth enzyme in the pyrimidine biosynthetic pathway, dihydroorotate dehydrogenase. The results support the hypothesis that the in vitro effects of leflunomide on T-lymphocytes are due to inhibition of de novo pyrimidine synthesis.
7677443 In vivo model of cartilage degradation--effects of a matrix metalloproteinase inhibitor. 1995 Aug OBJECTIVES: To develop a model of cartilage degradation that (i) enables the testing of synthetic, small molecular weight matrix metalloproteinase (MMP) inhibitors as agents to prevent cartilage erosion, (ii) permits the direct assay of the principal constituents of the extracellular matrix (collagen and proteoglycan) in both the non-calcified articular cartilage and the calcified cartilage compartments, and (iii) is mediated by a chronic, granulomatous tissue that closely apposes intact articular cartilage, and in this respect resembles the pannus-cartilage junction of rheumatoid arthritis. METHODS: Femoral head cartilage was obtained from donor rats, wrapped in cotton and implanted subcutaneously into recipient animals. After a two stage papain digestion procedure, the proteoglycan and collagen contents were measured by assaying for glycosaminoglycans and hydroxyproline, respectively, in both the non-calcified cartilage that comprises the articular surface layer and the calcified cartilage compartment. The incorporation in vitro of [35S]-sulphate into glycosaminoglycans was assayed as a measure of proteoglycan biosynthesis. An osmotic minipump was cannulated to the implanted femoral head cartilage and synthetic MMP inhibitors (MI-1 and MI-2) were infused continuously over a 14 day period. RESULTS: The implanted, cotton wrapped femoral head cartilages provoked a granulomatous response that resulted in the removal of collagen and proteoglycan from the cartilage matrix. The removal of proteoglycan and collagen was exclusively from the non-calcified articular cartilage, whereas the proteoglycan and collagen content of the calcified compartment increased during the experiments. MI-1 reproducibly reduced the degradation of proteoglycan and collagen in implanted femoral head cartilage. CONCLUSIONS: We have described an in vivo model of cartilage degradation that permits the measurement of proteoglycan and collagen in both non-calcified articular cartilage and calcified cartilage compartments. The model can be used to test the effects of agents of unknown systemic bioavailability and pharmacokinetic profile by infusing them directly to the site of cartilage degradation. The removal of cartilage extracellular matrix by granulomatous tissue was inhibited by an MMP inhibitor, thus proving the involvement of this family of proteinases in cartilage catabolism in this model.
7645531 Treatment of amyloidosis. 1995 Aug Amyloidosis is the extracellular deposition of normally soluble autologous protein in a characteristic abnormal fibrillar form. Systemic amyloidosis and some local forms are progressive, cause major morbidity, and are often fatal. No treatment specifically causes the resolution of amyloid deposits, but therapy that reduces the supply of amyloid fibril precursor proteins can improve survival and preserve organ function. Major regression of amyloid occurs in at least a proportion of such cases, suggesting that the clinical improvement reflects mobilization of amyloid. The clearest evidence for regression of amyloid has been obtained in juvenile rheumatoid arthritis patients with AA amyloidosis treated with chlorambucil. This drug suppresses the acute phase production of serum amyloid A protein, the precursor of AA amyloid fibrils, and is associated with remission of proteinuria and greatly improved survival. In many such patients, scintigraphy with serum amyloid P component shows major regression of amyloid over 12 to 36 months and frequently reveals a discrepancy between the local amyloid load and organ dysfunction. Measurement of target organ function is therefore not an adequate method for monitoring treatment aimed at promoting the resolution of amyloid. In monoclonal immunoglobulin light chain (AL) amyloidosis the aim of treatment is to suppress the underlying B-cell clone and, therefore, production of the amyloid fibril precursor protein. This can be difficult to achieve or sustain and, since the prognosis is so poor, many patients die before benefits of therapy are realized. A recent development has been the introduction of liver transplantation as treatment for familial amyloid polyneuropathy caused by transthyretin gene mutations. This leads to the disappearance of variant transthyretin from the plasma and halts progression of the neurologic disease. Features of autonomic neuropathy frequently ameliorate, and improvement in peripheral motor nerve function has been recently reported. Serum amyloid P component scans show regression of associated visceral amyloidosis. This surgical form of gene therapy holds much promise for patients with familial amyloid polyneuropathy and has been widely adopted. The only other form of amyloidosis in which the supply of the fibril precursor protein can be sharply reduced is beta 2M amyloidosis in long-term hemodialysis patients. Renal transplantation lowers the plasma concentration of beta 2M to normal levels and is associated with rapid improvement of the osteoarticular symptoms. Preliminary observations suggest that the beta 2M amyloid deposits also can regress in some patients.(ABSTRACT TRUNCATED AT 400 WORDS)
7612936 Examination of recombinant truncated mature human fibroblast collagenase by mass spectrome 1995 Human fibroblast collagenase belongs to a family of matrix metalloproteinases which have been implicated in a number of connective tissue disorders ranging from rheumatoid arthritis to tumor invasion. To examine the active site of this enzyme by biophysical studies, a 19 kDa recombinant truncated mature collagenase (mCL-t) was prepared. Electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry have been utilized for the characterization of mCL-t. The molecular weights measured by these techniques identified the presence of two closely related protein components separated by approximately 100 Da. Edman sequence analysis demonstrated that the two protein components differ from each other by an amino terminal valine, consistent with the mass spectrometric data. In addition, the molecular weight of mCL-t determined by mass spectrometry did not agree with that calculated from the reported sequence. To identify the origin of this discrepancy, the DNA sequence of the mCL-t clone was examined. Several differences were noted between the DNA sequence of mCL-t and the published collagenase gene sequence. When these differences were taken into account, the measured molecular weights were found to be in good agreement with that calculated for the modified sequence. In separate experiments, both ESI and MALDI mass spectrometry have been used to determine molecular weights of mCL-t samples enriched with stable isotopes 15N and (15N + 13C). The measured molecular weights demonstrated a 97% (15N) and 99% (15N + 13C) incorporation of labeled isotopes in the two samples.
7899229 Transsynovial drug distribution: synovial mean transit time of diclofenac and other nonste 1994 Dec The synovial mean transit time of diclofenac was determined by two methods from existing plasma and synovial fluid concentration-time data. These data were obtained from single- and multiple-dosing regimens of diclofenac in patients with osteoarthritis and rheumatoid arthritis. Plasma and synovial fluid concentration-time data taken from the literature for four other nonsteroidal antiinflammatory drugs (etodolac, ibuprofen, indomethacin, and tenoxicam) were also analyzed. The two methods of data analysis rely on the determination of the ratio of the area under the synovial fluid concentration-time curve to the area under the plasma concentration-time curve. Both methods can be considered noncompartmental because in determining the first-order exit rate constant for the synovial fluid (the inverse of the synovial mean transit time), an analysis of the overall distribution and elimination characteristics of the drug is unnecessary. Method 1 makes use of the information contained in the postdistributional synovial fluid to plasma concentration ratio whereas method 2 is a linear pharmacokinetic model using a partial-areas analysis. The single dose mean +/- S.D. synovial fluid exit rate constant for diclofenac was 0.39 +/- 0.33 hr-1 (n = 6), which was not significantly different from that determined by method 2; which was 0.49 +/- 0.52 hr-1. The steady state mean +/- S.D. diclofenac synovial fluid exit rate constants for methods 1 and 2 were 0.43 +/- 0.18 and 0.54 +/- 0.71 hr-1 (n = 8), respectively, which were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)