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Biomedical subjects

J S Louie

Publications and source records attributed to J S Louie.

At least 19 recordsLinked to original sources
PubMed2000

Guidelines for the use of immunosuppressive drugs in patients with ocular inflammatory disorders: recommendations of an expert panel.

PURPOSE: To provide recommendations for the use of immunosuppressive drugs in the treatment of patients with ocular inflammatory disorders. PARTICIPANTS: A 12-person panel of physicians with expertise in ophthalmologic, pediatric, and rheumatologic disease, in research, and in the use of immunosuppressive drugs in patient care. EVIDENCE: Published clinical study results. Recommendations were rated according to the quality and strength of available evidence. PROCESS: The panel was convened in September of 1999 and met regularly through May 2000. Subgroups of the panel summarized and presented available information on specific topics to the full panel; recommendations and ratings were determined by group consensus. CONCLUSIONS: Although corticosteroids represent one of the mainstays in the management of patients with ocular inflammation, in many patients, the severity of the disease, the presence of corticosteroid side effects, or the requirement for doses of systemic corticosteroids highly likely to result in corticosteroid complications supports the rationale for immunosuppressive drugs (for example, antimetabolites, T-cell inhibitors, and alkylating agents) being used in the management of these patients. Because of the potential for side effects, treatment must be individualized and regular monitoring performed. With careful use of immunosuppressive drugs for treatment of ocular inflammatory disorders, many patients will benefit from them either with better control of the ocular inflammation or with a decrease in corticosteroid side effects.

Drug Therapy, Combination↗
PubMed1998

The polymerase chain reaction in infectious and post-infectious arthritis. A review.

Polymerase chain reaction and other DNA amplification techniques to identify elusive infections should prove to be an effective tool for the clinical and investigative rheumatologist. The capability to identify and characterize infectious organisms in fluids and tissue will enable early, specific, and potentially curative treatment. Similarly, the capability to exclude infection and differentiate postinfectious diseases will enable other therapies to control the inflammation. Understanding these molecular techniques will most certainly improve clinicians' effectiveness for diagnosis and care.

Antigens, Bacterial↗
PubMed1997

Single-tube, nested, reverse transcriptase PCR for detection of viable Mycobacterium tuberculosis.

Several problems remain before molecular biology-based techniques, such as PCR, are widely accepted for the detection of infectious agents. Among the most formidable of these problems are the inability of the tests to distinguish between viable and nonviable organisms. We approached this problem by using the fact that bacterial mRNA has an extremely short half-life, averaging only a few minutes. We reasoned that by targeting bacterial mRNA by a reverse transcriptase PCR (RT-PCR), a positive signal would indicate the presence of a recently viable organism. To test our hypothesis, we chose to target the mRNA coding for the ubiquitous 85B antigen of mycobacteria. After partially sequencing the gene coding for 85B, we developed primers that were specific for Mycobacterium tuberculosis. In a single-tube, nested, RT-PCR (STN RT-PCR), these primers detected fewer than 40 CFU in spiked sputum samples and as few as 12 CFU in clinical sputum specimens. The sensitivity of STN RT-PCR with smear-negative samples was as good as that of culture. The specificity was 100%. More importantly, when M. tuberculosis was cultured with and without 1 microgram of isoniazid per ml, this assay could distinguish between those cultures which contained the antibiotic and those which did not. Subcultures on Lowenstein-Jensen agar confirmed the viability assessments of the STN RT-PCR. Control experiments demonstrated that isoniazid did not inhibit the RT-PCR. In addition, when an IS6110-targeted, DNA PCR was used to examine the same samples, all samples though 13 days (the last sample) continued to be positive, irrespective of whether isoniazid was present, thereby demonstrating the superiority of an mRNA target in the detection of mycobacterial viability.

Bacterial Typing Techniques↗
PubMed1994

Identification of Neisseria gonorrhoeae in synovial fluid using the polymerase chain reaction.

OBJECTIVE: To analyze synovial fluid (SF) for the presence of Neisseria gonorrhoeae DNA using the polymerase chain reaction (PCR). METHODS: We used a modified, nested PCR to detect the presence of N gonorrhoeae DNA in 41 samples of SF obtained from 10 patients with clinical gonococcal arthritis whose SF samples were sterile by culture and from 27 controls, including 11 patients with Reiter's syndrome. Results obtained using this method were compared with those obtained using the GEN-PROBE system, an RNA-DNA hybridization technique. RESULTS: With nested PCR, N gonorrhoeae DNA was detected in 11 of 14 SF samples obtained from patients with culture-negative clinical gonococcal arthritis but in none of the 11 SF samples from Reiter's syndrome patients. The specificity of this technique was 96.4%, with a sensitivity of 78.6%. The rate of false-positive results was 3.6%. The GEN-PROBE technique was unable to detect N gonorrhoeae ribosomal RNA in any of the samples. CONCLUSION: These findings demonstrate the potential utility of the PCR in confirming the clinical diagnosis of gonococcal arthritis as well as providing insight into the pathogenesis of this disorder in patients whose SF are sterile by standard culture techniques. PCR may also prove helpful in differentiating N gonorrhoeae arthritis from acute Reiter's syndrome.

Adolescent↗
PubMed1994

Imaging rheumatic joint diseases with anti-T lymphocyte antibody OKT-3.

T lymphocytes play an important role in the pathogenesis of rheumatoid arthritis (RA). Murine monoclonal antibody OKT-3 (IgG2a), known to be specific for T lymphocyte 20 kD glycoprotein CD3 receptor was labelled with 5 mCi 99Tcm and given intravenously (i.v.) to seven RA and two psoriatic arthritis patients following informed consent to identify inflamed synovium. Anterior and posterior whole body scans and specific regional imaging was commenced 20 min later. At 1 h, approximately 20% of 99Tcm was associated with the lymphocytes. In these patients, all 41 asymptomatic joints and 43 joints with mild pain or minimal tenderness had normal scans. All 34 joints with moderate to severe pain had moderate to marked uptake of radioactivity. Two patients experienced shaking chills for 20-30 min within an hour of 99Tcm-OKT-3 infusion. These results suggest that 99Tcm-OKT-3 imaging serves as an objective surrogate for joint inflammation and could be useful as a measurement of therapeutic effectiveness in RA and other diseases with inflamed synovium. The side effect profile may limit the utility of 99Tcm-OKT-3 but other forms of antibodies directed toward lymphocyte subsets may be useful.

Adult↗
PubMed1993

The polymerase chain reaction for the detection of Borrelia burgdorferi in human body fluids.

OBJECTIVE: To analyze clinical fluids for the presence of Borrelia burgdorferi DNA using the polymerase chain reaction (PCR). METHODS: We utilized a modified, nested PCR to detect the presence of Borrelia DNA in 99 samples of serum, urine, cerebrospinal fluid (CSF), or synovial fluid obtained from 44 patients with various stages of Lyme disease and 47 control subjects. Primer specificity was corroborated by examining 2 DNA data banks, testing against DNA from other organisms, and confirming results with a second set of nested primers. RESULTS: Nested PCR was capable of detecting DNA from fewer than 10 organisms in 1 ml of fluid. The specificity of this technique was 96.4%, with a sensitivity of 76.7%. Although the specificity was uniformly high, the sensitivity was dependent upon the body fluid being tested: CSF 100%, urine 100%, synovial fluid 80%, and serum 59%. The rate of false-positive results was 3.6%. CONCLUSION: These data demonstrate the potential utility of PCR in confirming the clinical diagnosis of Lyme disease as well as providing insight into the pathogenesis of various stages of this disorder.

Base Sequence↗
PubMed1993

Oxygen uptake during exercise in patients with primary fibromyalgia syndrome.

OBJECTIVE: Muscle ischemia has been postulated as a causative factor in pain and disability in patients with primary fibromyalgia syndrome (PFS) and previous studies have demonstrated that patients with PFS have reduced maximum oxygen uptake (VO2). Our objective was to examine the level and pattern of VO2 in response to graded exercise and defined levels of constant work rate exercise in patients with PFS. METHODS: Unmedicated patients fulfilling modified Yunus' criteria for the diagnosis of PFS and healthy control subjects performed upright cycle ergometry exercise with measurements of respiratory gas exchange and grading of pain using visual analog scores. RESULTS: Patients, but not controls, had significantly higher levels of pain after graded exercise than before exercise. Although peak VO2 did not differ between the 2 groups, effort dependent variables of exercise function were more variable in the patients than in control subjects. The onset of muscle anaerobiosis as reflected in respiratory gas exchange, the relationship between VO2 and work rate throughout the range of exercise work rates, and the mean response time for the increase in VO2 to the exercise level in response to a constant work rate of exercise were not different for patients compared to controls. CONCLUSION: Despite the subjective reports of pain, our studies demonstrate no abnormality in the overall rate and pattern of utilization of oxygen during muscular exercise in patients with PFS.

Adult↗
PubMed1990

Idiotypic characteristics of immunoglobulins associated with human systemic lupus erythematosus. Association of high serum levels of IdGN2 with nephritis but not with HLA class II genes predisposing to nephritis.

Serum levels of IdGN2 (an idiotype enriched in nephritogenic antibodies), IdX (an idiotype not enriched in nephritogenic antibodies), IgG, and anti-DNA were measured in 23 Caucasian patients with lupus nephritis, in age- and sex-matched lupus patients without nephritis, and in similarly matched healthy individuals. Serum levels of IdGN2 were significantly higher in the patients with lupus nephritis than in those without, and they were higher in all lupus patients compared with the healthy control subjects. However, the same observations were true for serum levels of IdX. There were significant positive correlations between the serum levels of IgG, IdGN2, IdX, and anti-DNA. HLA typing at the DR and DQ loci was performed in 105 lupus patients of different races (Caucasian, black, and Asian/Polynesian/Filipino). Serum levels of IdGN2 in 83 of these individuals did not correlate with any of the HLA class II haplotypes currently known to predispose to lupus nephritis. We conclude that the high serum levels of IdGN2, which are characteristic of some patients with lupus nephritis, may often result from polyclonal B cell activation rather than from idiotype-specific upregulation associated with one or more of the class II genes that predispose to nephritis in this disease.

Genes, MHC Class II↗
PubMed1990

Lupus membranous glomerulonephritis: different prognostic subgroups obscured by imprecise histologic classifications.

Eighteen patients with lupus membranous nephritis were retrospective identified by reviewing the renal biopsy records of an active renal pathology service. Seven had minimally proliferative membranous nephropathy (World Health Organization (WHO) classes Va and b). Eleven had membranous nephropathy with superimposed changes of focal or diffuse proliferative glomerulonephritis (WHO Vc and d). After mean follow-up periods of 73 +/- 6 and 74 +/- 15 mo, respectively, one patient of seven from WHO Va and b and seven of 11 from WHO Vc and d reached end stage renal disease. The latter patients were distinguishable from the former only by the degree of superimposed proliferation on renal biopsy and not by blood pressure, antinuclear antibody, anti-double stranded DNA, or complement levels. These data stand in contrast to the widely held belief that lupus membranous nephropathy is relatively benign. The belatedness of this observation is partially due to imprecision in nosology for patients with lupus who have renal biopsies with "overlap" characteristics.

Biopsy↗
PubMed1989

Idiotypic characteristics of immunoglobulins associated with systemic lupus erythematosus. Studies of antibodies deposited in glomeruli of humans.

Indirect immunofluorescence with monoclonal antibodies to 6 different idiotypes was used to characterize immunoglobulins deposited in the glomeruli of renal biopsy samples from 32 patients with systemic lupus erythematosus (SLE) and 19 patients with nonlupus immune glomerulonephritis. IdGN2 was present in 75% of the biopsy specimens from SLE patients and in 6% of those from patients with non-lupus nephritis; IdGN1 occurred in 38% and 6%, respectively. The other idiotypes were not increased in biopsy samples from patients with SLE. Deposition of IdGN2 was associated with a subendothelial location of Ig and proliferative changes in the glomeruli. In studies of glomerular eluates from 4 immunosuppressed SLE patients, an average of 26% of total Ig and 37% of anti-DNA was composed of IdGN2. Compared with IdGN2- immunoglobulin, IdGN2+ immunoglobulin was enriched in IgG1 in all 4 eluates, and was enriched in high-avidity anti-DNA in 2 eluates. IdGN2 is a marker of antibody subsets that are characteristic of SLE and are associated with severe lupus nephritis.

Adult↗
PubMed1989

Poor prognosis in end-stage lupus nephritis due to nonautologous vascular access site associated septicemia and lupus flares.

A poor prognosis was observed in patients who had end-stage renal disease (ESRD) as a result of systemic lupus erythematosus (SLE). This was true even in patients in whom SLE disease activity was transiently quiescent during the period of hemodialysis. Six of 9 patients with ESRD and SLE died with active SLE and/or sepsis 1-28 months following the onset of dialysis. In 5 of the 6 patients, acute inflammatory activity of SLE flared within 1 month of the patient's death. Four patients died with superimposed sepsis, but only 2 of the 4 were receiving high-dose concomitant immunosuppressives for more than 1 week prior to death. Infected hemodialysis vascular access sites were implicated as the source of septicemia in 3 of 4 infectious deaths. The 3 surviving patients had minimal lupus activity prior to the development of ESRD, a possible marker for stability in SLE patients who require hemodialysis. Our results suggest that hemodialyzed lupus patients with nonautologous vascular access sites may be at continued increased risk for life-threatening inflammatory and septic complications.

Adult↗
PubMed1988

Specific suppression of anti-DNA production in vitro.

To investigate the regulation of anti-DNA antibody production, we generated anti-DNA-specific suppressor cells by exposing normal human T cells and a small percentage of adherent cells to high concentrations of DNA. These cells suppressed the production of anti-DNA by both autologous peripheral blood mononuclear cells (PBMC) and allogeneic PBMC derived from systemic lupus erythematosus (SLE) patients. Anti-DNA production was suppressed significantly more than anti-RNA, antitetanus, or total immunoglobulin production. Specific suppression was enhanced by increasing the numbers of DNA-primed CD8+ cells and was obliterated by irradiation of the DNA-primed cells. In contrast to T cells from normal individuals, T cells obtained from two intensively studied SLE patients were unable to generate specific suppressor cells for anti-DNA production in both autologous and allogeneic test systems. Despite this defect, these patients were still capable of generating specific suppressor cells for antibody production directed against an exogenous antigen, tetanus toxoid.

Antibodies, Antinuclear↗
PubMed1987

Retinoid modulation of collagenase production by adherent human mononuclear cells in culture.

Previous observations have suggested that retinoids might be useful for the treatment of rheumatoid arthritis. In this study we examined the effects of various retinoids on collagenase production by adherent human peripheral blood mononuclear cells in culture. We have previously shown that these cells, consisting predominantly of monocyte-macrophages, actively synthesize and secrete collagenase upon stimulation with concanavalin A. The cells were incubated in serum free medium with all-trans-retinoic acid, 13-cis-retinoic acid, all-trans-retinal, or Ro 10-9359 (trimethylmethoxyphenyl retinoic acid ethyl ester) for up to 72 hours, and the collagenase activity was determined with [3H]proline labelled type I collagen as substrate. The incubation of mononuclear cells with all-trans-retinoic acid in the concentration range 10(-7)-10(-5) mol/l resulted in a dose dependent inhibition of the collagenase production. All-trans-retinal was also a potent inhibitor, whereas 13-cis-retinoic acid and Ro 10-9359 in a concentration of 10(-5) mol/l had a lesser effect. Control experiments indicated that the inhibition of collagenase production by all-trans-retinoic acid did not result from inhibition of total protein synthesis nor could it be explained by induction of an inhibitory molecule. These results indicate that retinoids with distinct structural features can inhibit collagenase production by monocyte-macrophages, and suggest a role for retinoids in the treatment of rheumatoid arthritis.

Cells, Cultured↗
PubMed1986

Collagenase production by human mononuclear cells in culture: inhibition by gold containing compounds and other antirheumatic agents.

Human peripheral blood mononuclear cells in adherent cultures have been shown to synthesise and secrete collagenase. In the present study we have examined the modulation of collagenase production in these cultures by several antirheumatic agents. Incubation of monocytes in serum free medium with sodium aurothiomalate in concentrations varying from 7.7 X 10(-7) to 7.7 X 10(-3) mol/l resulted in marked dose dependent inhibition of the collagenase production. This inhibition was apparently selective in that total protein synthesis or the viability of the cells were not affected. Similar inhibition of the collagenase production was also noted with auranofin, aurothioglucose, and chloroauric acid. The inhibition with auranofin was achieved with a concentration as low as 7.4 X 10(-8) mol/l. To examine the mechanisms of the inhibition of the collagenase activity induced by sodium aurothiomalate the production of prostaglandin E2 was also measured in the same cell cultures. Sodium aurothiomalate in concentrations greater than 7.7 X 10(-4) mol/l significantly inhibited the prostaglandin E2 production; the prostaglandin E2 production was not inhibited, however, in 7.7 X 10(-5) mol/l concentration, while the collagenase production was reduced by 51.0%. Also, exogenous prostaglandin E2 added to the cultures only slightly reversed the inhibition of the collagenase production by sodium aurothiomalate. Thus the inhibition of collagenase production by sodium aurothiomalate in human adherent mononuclear cell cultures appears to be independent of the inhibition of prostaglandin E2 production. The inhibition of collagenase produced by monocyte-macrophages, as shown here in vitro, may contribute to the clinical efficacy of the compounds tested in the treatment of rheumatoid arthritis.

Anti-Inflammatory Agents↗
PubMed1984

Clonally restricted anti-IgG antibodies in rheumatoid arthritis.

Clonally restricted anti-IgG antibodies were detected, by isoelectric focusing (IEF) and chromatofocusing techniques, in the sera of patients with rheumatoid arthritis (RA). Anti-Fab antibodies were predominantly acidic proteins with isoelectric points of 4.5-6.5 and displayed restricted spectrotype patterns. Proteins reactive with the Fc portion of IgG showed polyclonal spectrotype patterns with alkaline pI of 7.5-9.0. A limited array of anti-Fab spectrotypes was consistently detected in RA sera when analyzed by IEF on 6M urea gels. Additional anti-Fab antibody bands were detected when the RA sera were dialyzed against 4-6M urea prior to IEF analysis, indicating that some anti-Fab antibodies exist in a complexed form in serum. Under these dissociating conditions, anti-Fab antibodies could also be detected in normal subjects, but the spectrotype patterns were more restricted than those in RA sera. Because anti-Fab antibodies may regulate normal immune responses, the increased quantity of clonally restricted anti-Fab antibodies in RA may indicate an abnormality of this immunoregulation.

Antibodies, Anti-Idiotypic↗
PubMed1984

The production of collagenase by adherent mononuclear cells cultured from human peripheral blood.

Mononuclear cells were isolated from human peripheral blood by Ficoll-Hypaque centrifugation, and the cells adherent to plastic substrata were cultured in serum-free media supplemented with lactalbumin hydrolysate. These cell cultures, which consisted predominantly of monocyte-macrophages as judged by nonspecific esterase staining, accumulated collagenase in the medium. This collagenase resembled other vertebrate collagenases in that it cleaved native triple-helical type I collagen at a locus 3/4-length away from the amino-terminal end of the molecule. The collagenase activity was inhibited by Na2EDTA, dithiothreitol, and fetal calf serum, while the addition of Ca++ or N-ethylmaleimide enhanced the enzyme activity. The accumulation of collagenase in the culture media was markedly enhanced by the incubation of cells with concanavalin A or phorbol myristic acetate. In the presence of cycloheximide, the levels of collagenase activity were markedly reduced, suggesting that active protein synthesis was required to express the enzyme activity. In additional experiments, monocytes were further purified by counterflow centrifugation-elutriation. The collagenase production was markedly increased in cultures enriched in monocyte-macrophages and devoid of polymorphonuclear leukocytes. The accumulation of collagenase in monocyte cultures incubated for 48 hours in the presence of concanavalin A or phorbol myristic acetate was of the same order of magnitude as in parallel cultures containing the same number of polymorphonuclear leukocytes purified by Ficoll-Hypaque centrifugation and Plasmagel sedimentation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Adhesion↗
PubMed1984

12-O-Tetradecanoylphorbol-13-acetate (TPA) directly inhibits spontaneous immunoglobulin secretion by in vivo antigen-induced human lymphoblastoid B cells.

Tetanus toxoid (Tet) booster immunization induces the transient appearance in the circulation of lymphoblastoid (LB) B cells which spontaneously produce anti-tetanus toxoid IgG antibody (IgG-Tet) during a 3-day in vitro culture. In this study we have examined the effects of TPA on the ability of LB cells to secrete antibody and have found that as little as 10 ng/ml of TPA provoked a marked inhibition of the induced LB cells' IgG-Tet production. This inhibitory effect was observed only when TPA was added early in the culture and could be achieved by pretreating the B cells with TPA for as little as 1 hr. Only marginal inhibition of IgG-Tet production was observed if the addition of TPA was delayed 14-24 hr. The TPA inhibition was not mediated by contaminant T cells as the addition of increasing numbers of T cells to LB cell cultures proportionally reversed the TPA inhibitory effect. Likewise, the inhibition of antibody synthesis was not due to a monocyte-dependent mechanism since (1) substantial depletion of adherent cells did not reverse the inhibition of antibody synthesis, (2) the addition of a monocyte-enriched population to monocyte-depleted B cells did not enhance, but in fact partially reversed, the inhibition caused by TPA, and (3) the addition of monocyte populations pretreated with TPA to monocyte-depleted B-cell fractions did not inhibit subsequent IgG-Tet production by the LB cells.

Antibodies, Bacterial↗