Search PubMed⌕ Search

Biomedical subjects

M D Smith

Publications and source records attributed to M D Smith.

At least 145 records · Page 8Linked to original sources
PubMed1999

Rheumatoid arthritis, disability and the workplace.

Rheumatoid arthritis is a common cause of disability worldwide. The nature of the disability impacts on all areas of life. This chapter focuses on the nature of the disability of rheumatoid arthritis with emphasis on work disability. The various approaches for minimising the disability and rehabilitating those with disability are discussed. The tools for the assessment of disability are described and their strengths and limitations outlined.

Absenteeism↗
PubMed1999

Elevated plasma concentrations of interferon (IFN)-gamma and the IFN-gamma-inducing cytokines interleukin (IL)-18, IL-12, and IL-15 in severe melioidosis.

Interferon (IFN)-gamma plays an important role in the pathogenesis of sepsis. Production of IFN-gamma is stimulated by synergistic effects of interleukin (IL)-18, IL-12, and IL-15. To investigate the regulation of IFN-gamma production during severe gram-negative infection, the plasma concentrations of IFN-gamma, IL-18, IL-12, and IL-15 were measured in 83 patients with suspected melioidosis. The diagnosis was confirmed in 62 patients, 31 of whom had blood cultures positive for Burkholderia pseudomallei, of whom 12 died. Compared with healthy controls, patients had elevated levels of IFN-gamma, IL-18, IL-12p40, and IL-15 on admission, with significantly higher levels in blood culture-positive patients, and these levels remained elevated during the 72-h study period. In whole blood stimulated with heat-killed B. pseudomallei, anti-IL-12 had a stronger inhibitory effect than anti-IL-18 and anti-IL-15 on IFN-gamma production. This effect of anti-IL-12 was further enhanced by anti-IL-18. These data suggest that during gram-negative sepsis, IFN-gamma production is controlled at least in part by endogenous IL-18, IL-12, and IL-15.

Adolescent↗
PubMed1999

A comparison of chloramphenicol, trimethoprim-sulfamethoxazole, and doxycycline with doxycycline alone as maintenance therapy for melioidosis.

A prospective, open, randomized, comparative treatment trial was conducted to compare the therapeutic efficacy of the conventional four-drug combination (chloramphenicol, trimethoprim-sulfamethoxazole, and doxycycline) with that of doxycycline alone in oral maintenance treatment of melioidosis. Adult Thai patients with culture-confirmed melioidosis were randomized to receive treatment with either regimen for a minimum of 12 weeks, usually following intravenous treatment of severe disease. The main outcome measure was culture-confirmed relapse. One hundred sixteen patients were enrolled; 109 had culture-confirmed melioidosis, and 87 were considered evaluable (43 had received doxycycline). Culture-confirmed relapse occurred in one patient randomized to the conventional regimen and in 11 (25.6%) randomized to the doxycycline regimen (P = .009), and treatment failed for 8 (18.2%) versus 20 (46.5%), respectively (P = .009). Adverse effects occurred in 26% of patients overall. Doxycycline alone cannot be recommended for a first-line regimen of oral maintenance treatment of melioidosis.

Adolescent↗
PubMed1999

Comparison of imipenem and ceftazidime as therapy for severe melioidosis.

An open, prospective, randomized, comparative treatment trial was conducted to compare the therapeutic efficacy of high-dose intravenous imipenem and ceftazidime for acute severe melioidosis. Adult Thai patients with suspected acute, severe melioidosis were randomized to receive either imipenem, at a dosage of 50 mg/(kg x d), or ceftazidime, at a dosage of 120 mg/(kg x d), for a minimum of 10 days. The main outcome measures were death or treatment failure. Of the 296 patients enrolled, 214 had culture-confirmed melioidosis, and 132 (61.7%) of them had positive blood cultures. Mortality among patients with melioidosis was 36.9% overall. There were no differences in survival overall (P = .96) or after 48 hours (P = .3). Treatment failure after 48 hours was more common among patients treated with ceftazidime (P = .011). Both treatments were well tolerated. Imipenem is a safe and effective treatment for acute severe melioidosis and may be considered an alternative to ceftazidime.

Adolescent↗
PubMed1999

Shared rheumatoid epitope as a risk factor in determining outcome in rheumatoid arthritis.

BACKGROUND: A genetic component is thought to contribute to 30-40% of the expression of rheumatoid arthritis (RA) with the HLA-DR4, w4 (B1*0401), w14 (B1*0404) genes (and associated shared rheumatoid epitope) constituting a substantial portion of this risk. AIM: Our objective was to determine the presence of these risk factors in a group of patients with RA and to correlate presence with disease outcome. METHOD: Forty-three RA patients who had been regularly assessed up to a ten year period since their initial entry into two gold treatment trials were studied. DR4, w4, w14 and shared rheumatoid epitope were determined on peripheral blood lymphocytes using flow cytometry and specific monoclonal antibodies. Disease outcome was measured by Health Assessment Questionnaire (HAQ) score and C-Reactive Protein (CRP) as a serological measure of joint inflammation. RESULTS: To confirm accuracy of the flow cytometric technique, DR typing and epitope status was compared with results obtained by genotyping in a subset of 14 patients. There was complete concordance between these two techniques for the rheumatoid epitope. However, concordance was not complete (both false positives and false negatives) for DR4, w4 and w14. Hence the presence of rheumatoid epitope was only evaluated further in the larger group. The presence of the shared rheumatoid epitope correlated positively with poorer outcome on serological assessment (p < 0.05). No significant correlation between HAQ score and rheumatoid epitope status was observed although a weak trend was noted. CONCLUSION: These studies suggest that determination of rheumatoid epitope status by flow cytometry may provide useful data concerning the long term outcome of patients with RA.

Aged↗
PubMed1999

Diagnosis of Penicillium marneffei infection by quantitation of urinary antigen by using an enzyme immunoassay.

Penicillium marneffei is a major cause of opportunistic infection in patients with AIDS in north and northeastern Thailand. A method for the quantitation of P. marneffei antigen in urine was developed by using fluorescein isothiocyanate-labelled purified rabbit hyperimmune immunoglobulin G in an enzyme-linked immunosorbent assay. This method was evaluated with 33 patients with culture-proven penicilliosis and 300 controls (52 healthy subjects, 248 hospitalized patients without penicilliosis) from the same area in which penicilliosis is endemic. Urinary antigen was found in all 33 (100%) patients with penicilliosis, with a median titer of 1:20,480. With undiluted samples, 67 (27%) of 248 hospital patients and 3 (6%) of 52 healthy controls were reactive. At a cutoff titer of 1:40, the urine antigen detection assay had a diagnostic sensitivity of 97% and specificity of 98% (positive predictive value, 84%; negative predictive value, 99.7%). This test offers a valuable and rapid method for the diagnosis of penicilliosis in patients with AIDS and could be a useful addition to conventional diagnostic methods in areas in which penicilliosis is endemic.

Adult↗
PubMed1999

Cytokines and cell adhesion molecules in musculoskeletal disorders.

This paper reviews the cytokine profiles and various cell adhesion molecules expressed in the more common inflammatory joint conditions such as rheumatoid arthritis, psoriatic arthritis, the spondyloarthropathies (Reiter's syndrome, ankylosing spondylitis), as well as systemic lupus erythematosus, systemic sclerosis, Sjögren's syndrome, giant cell arteritis and polymyositis. Knowledge of the broad range of cytokines produced in these conditions and the expression of cell adhesion molecules that result from cytokine production will assist in the understanding of the pathogenesis of these conditions and may lead to new therapeutic interventions.

Journal Article↗
PubMed1999

Immunohistochemical detection of cytokines and cell adhesion molecules in the synovial membrane.

This paper describes the immunohistochemical techniques which can be used to detect cytokines and cell adhesion molecules in synovial membrane tissue, including a list of reagents and possible problems in each technique. It also describes three methods of quantitation of the resultant immunohistochemical detection, including the recent innovation computer-assisted digital video image analysis, and lists the advantages and disadvantages of each quantitation technique. This information will be a useful summary for any scientist interested in applying such techniques to the detection of cytokines and cell adhesion molecules in human tissue sections.

Alkaline Phosphatase↗
PubMed1999

Complications associated with pedicle screws.

BACKGROUND: The safety and the effectiveness of pedicle-screw instrumentation in the spine have been questioned despite its use worldwide to enhance stabilization of the spine. This review was performed to answer questions about the technique of insertion and the nature and etiology of complications directly attributable to the screws. METHODS: We performed a retrospective review of all of the pedicle-screw procedures that were done by us from January 1, 1984, to December 31, 1993. We inserted 4790 screws during 915 operative procedures on 875 patients; 668 (76.3 percent) of the patients had a lumbosacral arthrodesis. The mean duration of follow-up was three years (range, two to five years). The accuracy of screw placement was assessed on intraoperative, immediate postoperative, and follow-up radiographs with use of a technique that was developed by one of us (F. D.); this technique has yet to be validated to determine the prevalence of various types of error. RESULTS: Of the 4790 screws, 4548 (94.9 percent) had been inserted within the pedicle and the vertebral body. One hundred and thirty-four (2.8 percent) of the screws had perforated the anterior cortex, and this was the most common type of perforation. One hundred and fifteen (2.4 percent) of the screws were associated with complications that could be ascribed to the use of pedicle screws. The most common problem was late-onset discomfort or pain related to a pseudarthrosis or perhaps to the screws; this problem was associated with 1102 (23.0 percent) of the screws, used in 222 (24.3 percent) of the procedures. The symptoms necessitated removal of the instrumentation with or without repair of the pseudarthrosis. A pseudarthrosis was found during forty-six (20.7 percent) of the 222 procedures. Irritation of a nerve root occurred after nine procedures (1.0 percent) and was caused by eleven screws (0.2 percent); it was more commonly caused by medially placed screws. Three patients had residual neurological weakness despite removal of the screws. Twenty-five screws (0.5 percent), used in twenty procedures (2.2 percent), broke. The screws that broke were of an early design. A pseudarthrosis was found in thirteen of twenty patients who had broken screws. Sixteen of the twenty patients had an exploration; three of them were found to have a solid fusion, and thirteen were found to have a pseudarthrosis. The remaining four patients had evidence of a solid fusion on radiographs and had no pain. CONCLUSIONS: There are few problems associated with the insertion of screws, provided that the surgeon is experienced and adheres to the principles and details of the operative technique. Our review revealed a low rate of postoperative complications related to pedicle screws. The problem of late-onset pain may be related to the implants or to the stiffness of the construct; however, it is difficult to accurately identify its exact etiology.

Adolescent↗
PubMed1999

Hyperparathyroidism and chronic pancreatitis.

Hyperparathyroidism is a rare cause of pancreatitis. The nature of the relationship between the two entities is not well defined, i.e. is it casual or causal? We describe 2 patients with chronic pancreatitis and hyperparathyroidism who presented with epigastric pain and were initially treated unsuccessfully by surgical drainage of the pancreatic ducts. In 1 case the hyperparathyroidism was only recognised after the pancreatic surgery. In both the symptoms of chronic pancreatitis responded well to parathyroidectomy. We believe that our cases add support to a causal relationship between pancreatitis and hyperparathyroidism. Whatever the true relationship, management of these patients should initially be directed at the hyperparathyroidism, followed by appropriate treatment of the pancreatitis.

Abdominal Pain↗
PubMed1998

The N-terminal domain unique to the long form of the Brn-3a transcription factor is essential to protect neuronal cells from apoptosis and for the activation of Bbcl-2 gene expression.

The ability of the POU family transcription factor Brn-3a to stimulate neurite outgrowth and the expression of the genes encoding neuronal proteins such as the neurofilaments and SNAP-25 has previously been shown to be dependent upon the C-terminal POU domain which can mediate both DNA binding and transcriptional activation. We show here, however, that the ability of Brn-3a to activate Bcl-2 expression and protect neuronal cells from apoptosis (programmed cell death) requires a distinct N-terminal activation domain. Bcl-2 gene activation and protection from apoptosis are thus produced only by the long form of Brn-3a which contains this domain and not by a naturally occurring short form lacking this domain or by the isolated POU domain, although all these forms of Brn-3a can stimulate neurite outgrowth. Hence Brn-3a is a multi-functional transcription factor with different regions of the factor mediating its different effects and two distinct forms with different properties being generated by alternative splicing.

Animals↗