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Biomedical subjects

C A Kelly

Publications and source records attributed to C A Kelly.

At least 55 records · Page 3Linked to original sources

The treatment of sicca features in Sjögren's syndrome: a clinical review.

Patients with SS often suffer considerable distress due to sicca symptoms and the complications of mucosal dryness. Although there are many topical treatments available, the literature on their use is scant. This paper describes the treatments available and suggests a rationale for the choice of product.

Humans↗

Bronchial reactivity and airflow obstruction in rheumatoid arthritis.

OBJECTIVES: To investigate the prevalence of airways obstruction and bronchial reactivity to inhaled methacholine in rheumatoid arthritis patients and unselected controls. The control population consisted of patients attending the rheumatology department for minor degenerative joint problems. METHODS: One hundred patients with rheumatoid arthritis (RA) [72 (72%) women, 28 (28%) men; mean (SD) age 58 (10) years] and fifty controls [30 (60%) women, 20 (40%) men; mean (SD) age 56 (9) years] were studied. Detailed medical, smoking and drug histories were taken; skin prick tests were performed to assess atopy and chest and hand radiographs were performed. Spirometry, flow volume loops and gas transfer factor measurement were performed to detect airflow obstruction and methacholine inhalation tests were carried out to assess bronchial reactivity. RESULTS: There was no significant difference between rheumatoid arthritis patients and the controls in age, sex, smoking status and atopy on skin prick testing (p < 0.05). A significantly higher number of patients with RA had a history of wheeze compared with the controls (18% v 4%, p < 0.05). FEV1, FVC, FEV1/FVC, FEF25-75%, FEF25%, FEF50% and FEF75% were all significantly lower in the rheumatoid arthritis group (p < 0.05). A significantly higher number of patients with RA compared with controls showed bronchial reactivity to inhaled methacholine [55 (55%) v 8 (16%), p < 0.05]. FEV1, FVC, FEV1/FVC, FEF25-75%, FEF25%, FEF50% and FEF75% were all significantly lower among the patients with RA achieving PD20 FEV1 to inhaled methacholine (p < 0.05). CONCLUSION: In unselected rheumatoid arthritis patients both airflow obstruction and bronchial reactivity are significantly increased compared with controls.

Adult↗

Determinants of protein thermostability observed in the 1.9-A crystal structure of malate dehydrogenase from the thermophilic bacterium Thermus flavus.

A binary complex of malate dehydrogenase from the thermophilic bacterium Thermus flavus (tMDH) with NADH has been crystallized from poly(ethylene glycol) 3500, pH 8.5, yielding diffraction-quality crystals in space group P2(1)2(1)2(1). The structure was solved at 1.9-A resolution using molecular replacement and refined to an R factor of 15.8% with good geometry. The primary sequence of tMDH is 55% identical to that of cytoplasmic malate dehydrogenase (cMDH) [Birktoft, J. J., Rhodes, G., & Banaszak, L. J. (1989) Biochemistry 28, 6065-6081], and overall their three-dimensional structures are very similar. Like cMDH, tMDH crystallized as a dimer with one coenzyme bound per subunit. The coenzyme binds in the extended conformation, and most of the interactions with enzyme are similar to those in cMDH. In tMDH, small local conformational changes are caused by the replacement of a glutamic acid for the aspartic acid involved in hydrogen bonding to the adenine ribose of NADH. Comparison of tMDH with cMDH reveals that both tMDH subunits more closely resemble the B subunit of cMDH which therefore is the more likely representative of the solution conformation. While cMDH is inactivated at temperatures above about 50 degrees C, tMDH is fully active at 90 degrees C. On the basis of the X-ray crystal structure, a number of factors have been identified which are likely to contribute to the relative thermostability of tMDH compared to cMDH. The most striking of the differences involves the introduction of four ion pairs per monomer. All of these ion pairs are solvent-accessible. Three of these ion pairs are located in the dimer interface, Glu27-Lys31, Glu57-Lys168, and Glu57-Arg229, and one ion pair, Glu275-Arg149, is at the domain interface within each subunit. Additionally, we observe incorporation of additional alanines into alpha-helices of tMDH and, in one instance, incorporation of an aspartate that functions as a counterchange to an alpha-helix dipole. The possible contributions of these and other factors to protein thermostability in tMDH are discussed.

Amino Acid Sequence↗

Rheumatoid arthritis: other rheumatoid lung problems.

In summary, it appears that factors such as smoking and the presence of secondary Sjögren's syndrome might be important in predisposing the rheumatoid patient to the development of lung disease. Genetic factors may moderate or magnify these risks. At a cellular level, specific macrophage colonies within the lung may interact with a subgroup of CD4 T lymphocytes to produce unopposed B-cell activation, leading to local IgM production and the formation of immune complexes. This can damage lung both directly by cytolysis and indirectly by granulocyte recruitment through the release of neutrophil chemotaxins. Early in the evolution of these processes, steroids appear able to reduce lymphocyte numbers and prevent lung damage occurring, presumably by immunological mechanisms, while later they may reduce granulocyte numbers and activity, halting further progression of lung disease in some patients, perhaps by a direct anti-inflammatory effect. Confirmation of these mechanisms and the development of more specific therapeutic tools is probably dependent on studies which examine lung tissue directly by biopsy and may be aided by the application of more sensitive imaging techniques.

Arthritis, Rheumatoid↗

Paraproteins in rheumatoid arthritis and related disorders.

There is evidence that the prevalence of monoclonal parparoteinaemia is slightly increased in patients with rheumatoid arthritis. The possibility that this may be a marker of the development of later malignancy in such patients is explored. Mortality rates in rheumatoid arthritis are increased although the development of lymphoreticular malignancy contributes only a small percentage of this increase. However, it does seem likely that patients with longstanding severe rheumatoid arthritis are more at risk of developing myeloma or lymphoma if they have a monoclonal paraprotein band in their serum. IgA paraprotein seems to carry a higher risk than IgG whilst other factors such as urinary free light chains and the presence of secondary Sjögren's syndrome are of less prognostic significance. Similarly a monoclonal paraprotein may identify patients with primary Sjögren's syndrome who have a particular risk of later lymphoma whilst this risk does not appear to extend to patients with systemic lupus erythematosus. Patients with an overlap syndrome do not appear to be at greater risk than those with "pure disease". The association of other rheumatological disease and paraproteinaemia is briefly discussed.

Arthritis, Rheumatoid↗

Levels of CD5+ B cells are not increased in probands or relatives in a family study of primary Sjögren's syndrome.

Levels of CD5+ B lymphocytes were assayed in a large family study of Primary Sjögren's syndrome. There was no significant difference in CD5 expression by index cases or their relatives when compared to controls. No association between CD5 expression, serological abnormalities or HLA haplotype was found and, furthermore, no evidence of linkage with HLA was observed. There was, however, variation in the expression of CD5+ B cells between the families. Levels in spouses were lower and reached statistical significance. The role for genetic and environmental factors influencing CD5 expression is discussed. Any genetic influence does not appear to involve the HLA region or genes in linkage disequilibrium.

Adult↗

Preliminary X-ray diffraction analysis of a crystallizable mutant of malate dehydrogenase from the thermophile Thermus flavus.

Malate dehydrogenase from mutant strain F428 of the thermophilic bacterium Thermus flavus has now been crystallized from polyethylene glycol 8000 in a form suitable for diffraction studies. The protein crystallizes in the orthorhombic P2(1)2(1)2(1) space group with unit cell dimensions a = 71.8 A, b = 88.6 A, c = 119.0 A. The asymmetric unit consists of one homodimer of molecular mass 67,000 Da. The X-ray diffraction extends beyond 1.7 A and a full data set to 1.9 A has been collected.

Crystallization↗

Primary Sjögren's syndrome in north east England--a longitudinal study.

We have documented the initial clinical features of 100 patients with primary Sjögren's syndrome (SS) together with the results of their baseline investigations. The evolution of the disease in these patients has been followed for a median of 34 months (range 3-84 months). The majority of patients were females aged 40-60 years, and common clinical features included eye symptoms (100%), xerostomia (100%), polyarthralgia (94%), Raynaud's phenomenon (81%) and salivary gland swelling (47%). Thyroid disease was relatively common (14%) while other endocrine disease was rare. Four patients died during follow-up, and three cases of lymphoma were detected. Other serious complications included pericarditis (10%), pleuroparenchymal lung disease (9%), renal tubular acidosis (3%) and cerebrovascular accidents (2%). The presence of anti-Ro antibodies identifies patients with more severe systemic disease. Spontaneous improvement occurred in 12 patients, while steroids were required for specific complications in 18. Overall, although lymphoma was found to excess in our group, the high mortality reported with primary SS elsewhere was not seen.

Adolescent↗

Amino acid sequences of ovomucoid third domain from 25 additional species of birds.

Ovomucoids were isolated from 25 avian species other than the 101 studied in Laskowski et al. (1987, Biochemistry 26, 202-221). These were subjected to limited proteolysis with an appropriate enzyme, and connecting peptide extended ovomucoid third domains were isolated and sequenced to the end in a protein sequencer. Of the 25 new sequences, 13 duplicate ones were already known, and 12 are unique. Probably the most striking findings are a Pro14----Ser14 replacement in weka, an Ala14----Thr15 replacement in Bulwer's pheasant, the discovery of two additional amino acid residues Ile18 and Gly18 at the P1 reactive site position in Kalij pheasant and tawny frogmouth, respectively, and the first finding of a negative (Glu34) rather than positive (Lys34 or Arg34) amino acid residue at the NH2 terminus of the alpha helix in caracara ovomucoid third domain. These results complete the determination of all the sequences of ovomucoid third domains in the four species genus Gallus, in the five species genus Syrmaticus, and in the two species genera Aix and Pavo.

Amino Acid Sequence↗

The reversible effect of lignocaine on the stimulated metabolic activity of bronchoalveolar lavage cells.

Lignocaine concentrations were measured in the aspirate from a low volume (100 ml) bronchoalveolar lavage (BAL) in twenty patients who had received topical 4% lignocaine as required, and compared to those found in the aspirate from a 180 ml BAL in ten patients who had received 1.5% isotonic lignocaine. The median BAL supernatant lignocaine concentration was significantly lower at 0.14 mM (range 0.07-0.44 mM) in the group who received 1.5% lignocaine, compared to 1.08 mM (range 0.03-7.05 mM) in those given 4% lignocaine (p less than 0.01). The effect of increasing concentrations of lignocaine on BAL neutrophil and pulmonary macrophage metabolic activity, as assessed by latex-stimulated luminol- and lucigenin-amplified chemiluminescence (CL), respectively, in mixed BAL cell populations, were measured following preincubation of "washed" harvested BAL cells with 0.4-8.0 mM lignocaine. There was no demonstrable decline in either cell activity with lignocaine concentrations of up to 2 mM, with dose-dependent inhibition of both above this threshold. Cell viability was unaffected. In a further experiment, the inhibition induced by 8 mM lignocaine on both pulmonary macrophage (lucigenin-amplified CL of harvested BAL cells) and isolated peripheral blood neutrophil metabolic activity was completely reversed by a single "wash", following both 30 and 60 min incubations at 4 degrees C, which was equivalent to resuspending harvested BAL cells in fresh medium after separation from BAL supernatant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

The relative contribution of bronchoalveolar macrophages and neutrophils to lucigenin- and luminol-amplified chemiluminescence.

The relationship between differential cell counts and latex-stimulated luminol and lucigenin-amplified chemiluminescence (CL) was investigated by mixing alveolar macrophages (AM) obtained at bronchoalveolar lavage (BAL) with allogeneic peripheral blood neutrophils (PMN) in varying proportions. In 5 non-asthmatic subjects, the mean luminol-amplified CL increased linearly from 2.1 (0.9 SEM) x 10(5) counts per second (cps) with less than 2% PMN, greater than 96% AM to 47.3 (11.1 SEM) x 10(5) cps with greater than 94% PMN, 0% AM (r = 0.996, p less than 0.001). The regression had a y-intercept indistinguishable from 0 cps, suggesting that luminol-amplified CL exclusively reflected PMN activity. Using the same technique, the mean lucigenin-amplified CL showed a fall from 35 (2.3 SEM) x 10(5) cps with a cell population of greater than 96% AM, less than 2% PMN to 20 (2.3 SEM) x 10(5) cps with 0% AM, greater than 94% PMN. Both PMN and AM appeared to contribute to lucigenin-amplified CL, with AM contributing approximately 1.7 times as much activity per cell as PMN. Lucigenin-amplified CL appeared to be an appropriate technique for measuring AM activity when the proportion of PMN in mixed cell populations was small. A linear relationship was found between percent PMN count and luminol-amplified CL measured in a mixed BAL cell population from asthmatic subjects (p less than 0.01) and non-asthmatic controls (p less than 0.01). The slope of this regression line was significantly greater for subjects with asthma than for control subjects (p less than 0.01), suggesting a uniform increase in PMN activity in cells obtained from asthmatic airways.

Acridines↗

Platelet-activating factor in bronchoalveolar lavage fluid from asthmatic subjects.

Bronchoalveolar lavage (BAL) was performed on 28 asthma patients, 7 patients with emphysema and 11 control subjects. Total and differential cell counts were performed and cellular metabolic activity was assessed using luminol and lucigenin amplified chemiluminescence. BAL supernatants were assayed for platelet-activating factor (PAF) and lyso-PAF using a sensitive guinea-pig bioassay. Eight of the asthma patients but none of the emphysema patients or control subjects had PAF in their BAL fluid. Lyso-PAF was measurable in BAL fluid in most subjects and no differences were detected between groups. Among the asthma patients, the presence of PAF in BAL supernatant was significantly associated with a combination of low neutrophil and high lymphocyte counts (p less than 0.05) and with macrophage metabolic activity as assessed by lucigenin chemiluminescence (p less than 0.05).

Adolescent↗

Chronic pericardial disease in patients with rheumatoid arthritis: a longitudinal study.

We have reviewed the clinical and investigative findings in 13 patients with chronic pericardial disease and seropositive rheumatoid arthritis. In eleven cases the diagnosis was made on clinical grounds, while the diagnosis was confirmed only at post-mortem in two patients. Pleural effusions were present in seven patients, while pulsus paradoxus was found in only one case. Echocardiograms were undertaken in ten patients and all showed evidence of pericardial effusions, which were usually small and sited posteriorly. A delayed ventricular filling pattern indicating abnormal ventricular relaxation was seen in two patients with cardiac tamponade. The surviving 11 patients were reviewed a median of three years after diagnosis of their pericardial disease. Pericardectomy had been performed in six, all of whom were asymptomatic and had a normal chest radiograph. Steroids alone had been given to the other five, and three of these remained dyspnoeic with cardiomegaly. The clinical features distinguishing chronic pericardial disease from other causes of right heart failure in rheumatoid arthritis patients are subtle. As management is fundamentally different, serious consideration should be given to the diagnosis of chronic pericardial disease in any patient with rheumatoid arthritis who presents with right-sided heart failure.

Adult↗

Abnormally-fucosylated serum haptoglobins in patients with inflammatory joint disease.

The fucosylation of haptoglobins is altered in rheumatoid arthritis. In order to investigate the clinical usefulness of this finding, serum levels of abnormally-fucosylated haptoglobins (FHp) have been assessed in defined and matched groups of patients with different inflammatory joint diseases. FHp was elevated in 16/17 patients with active rheumatoid arthritis (RA); 1/20 patients with inactive rheumatoid arthritis; 1/11 patients with osteoarthritis; and 4/10 patients with seronegative polyarthritis. Raised FHp levels, therefore, are not disease-specific. There was no relationship between the duration of RA and the FHp level. The FHp expression in RA was also compared with other biochemical indices of disease activity. The degree of correlation between FHp and articular index, joint score and early-morning stiffness was very similar to that obtained for C reactive protein (CRP), and better than that obtained for erythrocyte sedimentation rate and haemoglobin. FHp, however, gives fewer false-positives than CRP in cases of inactive disease. until FHp can be measured more easily and cheaply, CRP estimation is still the biochemical test of choice in RA.

Adult↗