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Biomedical subjects

J Webb

Publications and source records attributed to J Webb.

At least 145 records · Page 8Linked to original sources
PubMed1989

Antihistone antibodies in rheumatoid arthritis and Felty's syndrome.

Although antihistone antibodies are frequently detected in patients with systemic lupus erythematosus, they appear to be uncommon or present only at low levels in rheumatoid arthritis (RA) patients. We used an enzyme-linked immunosorbent assay to study sera from 42 patients with RA, and we confirmed that antihistone antibodies mainly occurred at low levels in these patients. In contrast, 83% of 24 patients with Felty's syndrome had antihistone antibodies, often at high levels. Thus, antihistone antibodies may be a common autoimmune abnormality in patients with Felty's syndrome but not in other patients with RA. In addition, we demonstrated that some rheumatoid factors have cross-reactive antihistone antibody activity.

Arthritis, Rheumatoid↗
PubMed1989

Pyridoxal isonicotinoyl hydrazone and analogues. Study of their stability in acidic, neutral and basic aqueous solutions by ultraviolet-visible spectrophotometry.

The ultraviolet-visible absorption spectra of the orally effective iron chelator, pyridoxal isonicotinoly hydrazone (PIH), and three analogues, pyridoxal benzoyl hydrazone (PBH), pyridoxal p-methoxybenzoyl hydrazone (PpMBH) and pyridoxal m-fluorobenzoyl hydrazone (PmFBH) have been measured in aqueous solution with various concentrations of added acid or alkali. Assignment of absorption bands to various molecular species in equilibrium in aqueous solution is made by reference to their acid ionisation constants. All four hydrazones were stable at physiologial pH, but hydrolysed in strongly acidic and basic solutions, resulting in the liberation of pyridoxal and the acid hydrazide. In acidic solutions this resulted in a dramatic decrease in the intensity of absorption at wavelengths of 225 nm and above 300 nm, allowing a quantitative estimate of the degree of acid-catalysed hydrolysis of the ligands. These results indicate that for oral administration the chelator should be administered with calcium carbonate or provided with an enteric coating to minimise acid-catalysed hydrolysis in the stomach. At high pH, base-catalysed hydrolysis occurred, resulting in a decrease in the absorption at a wavelength of 387 nm.

Drug Stability↗
PubMed1989

Iron chelators of the pyridoxal isonicotinoyl hydrazone class. III. Formation constants with calcium(II), magnesium(II) and zinc(II).

Formation constants for the calcium(II), magnesium(II) and zinc(II) complexes of the orally effective iron chelator, pyridoxal isonicotinoyl hydrazone (PIH) and three analogues, pyridoxal benzoyl hydrazone (PBH), pyridoxal p-methoxybenzoyl hydrazone (PpMBH) and pyridoxal m-fluorobenzoyl hydrazone (PmFBH) have been determined by potentiometry at 25 degrees C and I = 0.1 M [KNO3]. The four ligands bind calcium(II) weakly and magnesium(II) only slightly more strongly, as a 1:1 complex which is formed at pH greater than 8. The chelation of zinc(II) for all the ligands studied was greater than that for calcium(II) and magnesium(II), with complexation generally becoming significant at about pH 5. Thus, chelation of zinc(II) but not calcium(II) or magnesium(II) at physiological pH, 7.4 may be expected. Calculated values of the concentration of uncomplexed metal ion indicate that the selectivity of these ligands towards Fe(III) is comparable to that of the clinically used chelator desferrioxamine.

Calcium↗
PubMed1989

Use of antibiotic resistance mutations to track strains of obligately anaerobic bacteria introduced into the rumen of sheep.

Selective plating procedures were used to follow the fate of rifampicin-resistant mutant strains of the obligately anaerobic species Bacteroides multiacidus and Selenomonas ruminantium after their introduction at numbers around 10(7)/ml into the rumen of sheep. Bacteroides multiacidus strain F100 showed an initially rapid rate of loss (49%/h) but subsequently numbers declined more gradually approaching the limits of detection (less than 10(3)/ml) after 100 h. Viable cell numbers also decreased in vitro upon addition of F100 cells to whole rumen contents, but remained stable upon addition to cell-free rumen fluid, suggesting protozoal predation. F100 cells were able to grow in vitro in whole rumen contents in the presence of an added utilizable substrate such as sorbitol, but addition of sorbitol to the rumen failed to enhance survival in vivo. In the case of S. ruminantium, introduced rifR strains persisted in the rumen at levels around 10(6) ml for at least 30 days.

Animals↗
PubMed1988

Preliminary results of a district call scheme for cervical screening organised in general practice.

A recognised problem with the cervical screening programme in the United Kingdom is the failure to include women who have never had a cervical smear test, who are a high risk group. The implementation of a district based call scheme in East Berkshire in 1986 is described whereby women aged 20-64 with no record of a cervical smear test who were judged to be eligible for testing by their general practitioner were sent a personal invitation from their general practitioner to attend for a test. A list of high risk unscreened women was kept by each practice, and a duplicate sent to the cytology laboratory to update the central records. Six months after each batch of invitations had been sent the resulting number of women having a smear test was assessed. Forty three of 51 practices approached agreed to participate in the five year scheme. During the first year lists were sent to the 43 participating practices. The first list was returned to the cytology laboratory by 37 practices and the second by 33; practices varied in their responses, however, some needing considerable persuasion to return the lists. Of 972 identified unscreened women from the total 3757 women listed in the lists of the family practitioner committee, 247 (25%) had a cervical smear test in response to the invitation, representing an overall increase of 7% in the screened population. The preliminary findings of the five year study have shown that screening can be improved by a systematic call scheme. Coordinated support from the area health authority in health education, monitoring of screening, and feedback of data from the scheme to practices is required to reduce the proportion of unscreened women.

Adult↗
PubMed1988

Assessment of a patient-completed questionnaire for keratoconjunctivitis sicca.

A patient-completed questionnaire has been shown to be equivalent to an observer-administered format in discriminating between subjects with and without keratoconjunctivitis sicca. As well as saving time it can screen patients for the presence of keratoconjunctivitis sicca without the need for more specialized and/or invasive techniques.

Humans↗
PubMed1988

Anti-Sm and anti-DNA antibodies in paired serum and synovial fluid samples from patients with SLE.

Antibodies to nuclear antigens (ANAs) are frequently found in the serum of patients with connective tissue diseases (CTDs). Particularly systemic lupus erythematosus (SLE), and have been implicated in the immune-complex mediated pathogenesis of these diseases. In this study we have compared the occurrence of precipitating ANAs in paired samples of serum and synovial fluid from patients with different CTDs. Of the 30 patients examined 3 had precipitating ANAs in their serum only, 1 in the synovial fluid only, and 3 had antibodies in both serum and synovial fluid. Precipitating ANAs in synovial fluid were found in 3/6 patients with SLE, 1 patient with RA/Sjogren's syndrome overlap, and one patient with RA/SLE overlap. Of the other 15 patients with RA, 2 had precipitating antibodies only in their serum. Two of the SLE patients had anti-Sm antibody, one in serum only and the other in both serum and synovial fluid. Detection by ELISA of class specific anti-Sm antibodies in serum or synovial fluid paralleled the occurrence of antidenatured DNA antibodies when both specificities occurred together. One SLE patient did show evidence in synovial fluids of elevated concentrations of specific antibody classes to individual antigens; however, elevated levels were more frequently found in serum. Local production of ANAs does not, therefore, appear to be a feature of synovial fluids from SLE patients.

Antibodies↗
PubMed1988

Benign joint hypermobility with neuropathies: documentation and mechanism of median, sciatic, and common peroneal nerve compression.

We report three patients in whom carpal tunnel syndrome was due to neurapraxis as a consequence of unusual sleep postures enabled by their benign joint hypermobility syndrome (BJHS). A fourth patient also had bilateral sensory sciatic neuropathy and a common peroneal palsy, similarly due to regularly adopted unusual postures. Recognition of such cause-effect mechanisms and their simple solution in BJHS should obviate needless investigation and unnecessary surgery.

Adult↗
PubMed1988

A rumen anaerobic fungus of the genus Neocallimastix: ultrastructure of the polyflagellate zoospore and young thallus.

The ultrastructure of the zoosporic, rumen fungal anaerobe, Neocallimastix sp. R1, was determined and compared to that of the two known species of Neocallimastix. Zoospores of the new isolate were generally ovoid in shape, but without the waisted appearance of N. frontalis zoospores. They possessed similar organelles to the other two species, but with different localisation. The flagellar rootlet system was broadly similar to N. frontalis and N. patriciarum, however, a previously undescribed, large organelle was found to be associated near the kinetosomal apparatus in some Neocallimastix sp. R1 zoospores. Well developed flagella, complete with basal bodies, were observed in young thalli.

Anaerobiosis↗
PubMed1988

Trends in abdominal aortic aneurysm surgery in Scotland (1971-1984).

The trends in diagnosis, operative workload and mortality of patients with abdominal aortic aneurysm in Scottish hospitals between 1971 and 1984 were analysed using the Scottish Hospital In-patient Statistics. The frequency of diagnosis of aneurysm increased from 25.8 per 100,000 population aged over 55 in 1971 to 63.6 per 100,000 in 1984. The proportion of diagnosed aneurysms treated by operation rose from 24% in 1971 to 41% in 1984, resulting in a 4-fold increase in operative workload. Despite the rise in diagnosis of abdominal aortic aneurysm, the ratio of elective to emergency procedures has only improved slightly during the 14 years, the majority still being operated on as emergencies. The operative mortality following elective procedures fell from 10.5% in 1971 to 4.3% in 1984, while that for emergencies fell from 50% to 36%. The reasons for the increased surgical workload are multifactorial. It is not solely a consequence of an ageing population as the proportion of Scots aged over 55 years increased by only 4% during this period. The evidence from this study suggests that the rise in workload is secondary to an increase in the frequency of diagnosis of abdominal aortic aneurysm in all age groups and to the fact that a greater proportion of diagnosed cases are now offered surgery.

Aged↗
PubMed1988

Geographical variation in the incidence of diabetes mellitus in Scottish children during the period 1977-1983.

Routinely collected Scottish hospital discharge data were used to identify newly diagnosed cases of diabetes mellitus under the age of 19 years. In the period 1977-83 there were 2183 cases, an average annual incidence of 21.0 per 100,000 per annum. This rate is one of the highest reported and represents a continuation of the increase in incidence which occurred during the period 1968-76. Statistically significant geographical variation in incidence was observed with the higher incidence in the least densely populated areas. Seasonal variation in the month of first admission was evident in all except the under-five age group with peaks occurring in winter. An estimated 60% of newly diagnosed cases were readmitted within 5 years and the pattern of readmission was found to differ little between males and females or between age groups.

Adolescent↗
PubMed1988

Response of rheumatoid arthritis to chemotherapy for Hodgkin's disease in a patient with IgA deficiency and overlap connective tissue disease.

A patient with IgA deficiency presented with classical rheumatoid arthritis (RA) and subsequently, features of multiple other connective tissue diseases (CTD). When Hodgkin's disease later developed the patient received combination chemotherapy, which induced remission of both neoplastic and connective tissue diseases. As the RA remained in remission for three years this case may offer insight into a mode of use of cytotoxic agents in CTD.

Adult↗