PubMed Health⌕ Search

Biomedical subjects

J MacCarthy

Publications and source records attributed to J MacCarthy.

11 recordsLinked to original sources
PubMed2001

Reduction and alkylation of proteins in preparation of two-dimensional map analysis: why, when, and how?

The standard procedure adopted up to the present in proteome analysis calls for just reduction prior to the isoelectric focusing/immobilized pH gradient (IEF/IPG) step, followed by a second reduction/alkylation step in between the first and second dimension, in preparation for the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) step. This protocol is far from being optimal. It is here demonstrated, by matrix assisted laser desorption/ionization-time of flight (MALDI-TOF)-mass spectrometry, that failure to reduce and alkylate proteins prior to any electrophoretic step (including the first dimension) results in a large number of spurious spots in the alkaline pH region, due to "scrambled" disulfide bridges among like and unlike chains. This series of artefactual spots comprises not only dimers, but an impressive series of oligomers (up to nonamers) in the case of simple polypeptides such as the human alpha- and beta-globin chains, which possess only one (alpha-) or two (beta-) -SH groups. As a result, misplaced spots are to be found in the resulting two-dimensional (2-D) map, if performed with the wrong protocol. The number of such artefactual spots can be impressively large. In the case of analysis of complex samples, such as human plasma, it is additionally shown that failure to alkylate proteins results in a substantial loss of spots in the alkaline gel region, possibly due to the fact that these proteins, at their pI, regenerate their disulfide bridges with concomitant formation of macroaggregates which become entangled with and trapped within the polyacrylamide gel fibers. This strongly quenches their transfer in the subsequent SDS-PAGE step.

Alkylation↗
PubMed1991

Variations between rheumatologists in using sulphasalazine.

The increased use of audit and resource management within the health service will focus attention on variations in clinical practice. We have looked at one rheumatological example; the extent rheumatologists vary in their clinical use of a slow-acting anti-inflammatory drug. We studied a single drug - sulphasalazine. In a prospective study sulphasalazine was given to 298 rheumatoid patients at 24 rheumatology centres in South East England. They were followed for 6 months. There were large differences between centres in: the types of patient started on therapy; the numbers of patients remaining on treatment; the responses after 6 months. The difference between some centres was more marked than the expected improvement in clinical and laboratory variables given by sulphasalazine. The use of a slow acting anti-rheumatic drug like sulphasalazine in rheumatoid arthritis is agreed by most rheumatologists in the UK and yet there are wide variations in its use. Our results question the validity of comparing clinical practice and associated costs between centres for even a simple clinical procedure.

Aged↗
PubMed1990

Tolerability of enteric-coated sulphasalazine in rheumatoid arthritis: results of a co-operating clinics study.

One thousand three hundred and eighty-two patients with rheumatoid arthritis requiring second-line therapy at 108 centres were entered into an open 6-months prospective tolerability study of enteric-coated sulphasalazine 2 g/day (Salazopyrin EN-tabs). Clinical and laboratory variables were measured, any adverse reactions and the reasons for withdrawal of medication were recorded. The outcome of therapy was known in 87.5% of patients entered of whom 65% continued with sulphasalazine beyond the 6-month study period. 3.2% withdrew for reasons unrelated to treatment, 5% for lack of effect and 26.8% due to an adverse event; gastrointestinal/central nervous 66.6%, rash 15.4%, haematological 5.1%, hepatic 4.7% and miscellaneous 8.1%. 1.2% of patients experienced potentially serious reactions: anaphylactic, haematological and hepatic. The majority of adverse events occurred early and were reversible upon cessation of medication. No clear relationship between withdrawal due to an adverse event attributed to sulphasalazine and the nature of the concomitant non-steroidal anti-inflammatory drug was identified.

Arthritis, Rheumatoid↗
PubMed1986

Intussusception--current trends in management.

Barium enema reductions were attempted in 65 (90%) of 72 intussusceptions, of which 51 (79%) were successful. This represents a success rate of 70% overall. The average hospital stay was 3 1/2 days. There was no mortality and, apart from a recurrence rate of 10%, no morbidity. It is suggested that barium enema reduction should be the treatment of choice provided that there is an emergency service of a paediatric radiologist and the patient is adequately resuscitated, the only absolute contraindication being evidence of pneumatosis intestinalis or peritonitis. Those patients who presented with shock, rectal bleeding, duration of symptoms longer than 48 hours, and pronounced degree of bowel obstruction had a higher rate of unsuccessful reduction. However, only the last two were significant. Further, provided that the clinical condition remains satisfactory and the reduction has been achieved to the caecum a repeat barium enema after some hours may be successful in achieving reflux of contrast into the ileum, confirming complete reduction.

Age Factors↗
PubMed1976

Apparatus for patient-controlled administration of intravenous narcotics during labour.

The intermittent intravenous administration of narcotic analgesics had advantages over intramuscular administration, but is often impracticable. The design of a prototype apparatus is described, from which analgesic, pethidine, can be self-administered intravenously during labour. The apparatus consists of a syringe pump and control system from which the patient can demand an increment of analgesic. The minimum interval between increments and the dose of the increment are preset. A demand for analgesia is only successful when the patient passes a reaction-time test, subsequently modified. The apparatus has been used by forty-two mothers in labour. The mean total dose self-administered (2.2 mg/kg) was well within the prescribed limits, suggesting that mothers regulated their demand. The apparatus appears acceptable and safe in labour. The apparatus will probably be of value in comparative studies of analgesics.

Anesthesia, Intravenous↗
PubMed1976

Phalangeal microgeodic syndrome of infancy.

A case is described of chilblain-like lesions in the fingers with punched-out erosions in the phalanges on x-ray which appears to be an example of Maroteaux's phalangeal microgeodic syndrome of infancy.

Bone Diseases↗
PubMedDate not supplied

Sexually transmitted diseases as seen by general practitioners in Ireland: use of a telephone survey.

A telephone survey of one of every five general practitioners in the Republic of Ireland was carried out in July 1978 for the purpose of establishing the frequency of diagnosis of venereal diseases during the preceding year. In addition, information was obtained on the subsequent management of the diseases. This type of survey was found to be economical and quick, and the response rate (98.6%) was excellent. The national frequency of diagnosis (per 100,000 population) was estimated from the sample to be 7.7 for syphilis, 97 for gonorrhea, and 2,000 for nonspecific venereal diseases. The rates of reporting of these diseases were less than or equal to 24.3%, 9.8%, and 3.1%, respectively, of the estimated frequencies. Sixty-nine percent of the general practitioners treated the patients themselves; 51% treated on the basis of clinical diagnosis alone.

Family Practice↗