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Biomedical subjects

J Robson

Publications and source records attributed to J Robson.

At least 19 recordsLinked to original sources

A comparison of molecular and enzyme-based assays for the detection of thiopurine methyltransferase mutations.

S-Methylation by thiopurine methyltransferase (TPMT) is an important route of metabolism for the thiopurine drugs. About one in 300 individuals are homozygous for a TPMT mutation associated with very low enzyme activity and severe myelosuppression if treated with standard doses of drug. To validate the use of molecular genetic techniques for the detection of TPMT deficiency, we have determined red blood cell TPMT activity in 240 adult blood donors and 55 normal children. Genotype was determined by restriction fragment length analysis of polymerase chain reaction products in a cohort of 79 of the blood donors and five cases of azathioprine-induced myelosupression, and this confirmed a close relationship between genotype and phenotype. In 17 of the 24 cases in which mutations were found, DNA was also available from remission bone marrow. In one of these cases, DNA from the remission marrow sample indicated the presence of a non-mutated allele that had not been seen in the blast DNA sample obtained at presentation. These results indicate that polymerase chain reaction-based assays give reliable and robust results for the detection of TPMT deficiency, but that caution should be exercised in relying exclusively on DNA obtained from lymphoblasts in childhood leukaemia.

Adolescent↗

Kingella kingae infections in children.

OBJECTIVE: To increase awareness of Kingella kingae infections in children by presenting four cases seen at the Gold Coast Hospital, Southport, Queensland, and reviewing the literature. METHODOLOGY: Records of the four cases were reviewed and relevant information described. A MEDLINE search of the English literature from 1983 to 1998 was conducted. RESULTS: Osteoarticular infections are the commonest type of invasive paediatric infection but bacteraemia and endocarditis also occur. Isolation of the organism is difficult but inoculation of the specimen into enriched blood culture systems improves the recovery rate. The majority of isolates are sensitive to beta-lactam antibiotics but resistance has been described. CONCLUSIONS: Kingella kingae infections in children are more common than previously recognized. The organism should be actively sought in any child with suspected osteoarticular infections. Recommended empiric therapy is a third generation cephalosporin until susceptibility to penicillin is confirmed.

Arthritis, Infectious↗

Rubella infection in pregnancy.

It is over 50 years since a syndrome of congenital abnormalities following maternal rubella infection was first recognised. Despite the potentially devastating effects of the congenital rubella syndrome, immunisation rates are not optimal and infections in pregnancy still occur. Four cases of rubella infection occurring in pregnancy are presented. Laboratory diagnosis of primary infection and reinfection is discussed, and the need for full immunisation in childhood, and of women of child-bearing age is reiterated.

Adult↗

Nonadherence with angiotensin-converting enzyme inhibitor therapy: a comparison of different ways of measuring it in patients with chronic heart failure.

OBJECTIVES: This study was designed to compare different proposed methods of assessing adherence with angiotensin-converting enzyme (ACE) inhibitor (ACEI) therapy in chronic heart failure. BACKGROUND: The use of ACEIs in chronic heart failure gives us a unique opportunity to assess a patient's adherence by measuring whether the expected biochemical effect of an ACEI is present in the patient's bloodstream. In fact, there are several different ways of assessing ACE in vivo: these are serum ACE activity itself, plasma N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP), urine AcSDKP, plasma angiotensin I (AI), plasma angiotensin II (AII), or the AII/AI ratio. METHODS: Patients with chronic heart failure (n = 39) were randomized to regimens of ACEI nonadherence for one week, ACEI adherence for one week or two versions of partial adherence for one week, after which the above six tests were performed. RESULTS: All six tests significantly distinguished between full nonadherence for one week and full or partial adherence. Only plasma AcSDKP produced a significantly different result between partial adherence and either full adherence or full nonadherence for one week. In terms of their ability to distinguish full nonadherence from full adherence, plasma AcSDKP was 89% sensitive and 100% specific with an area under its ROC of 0.95. Corresponding figures for urine AcSDKP were 92%, 97% and 0.95 and for serum ACE they were 86%, 95% and 0.90. CONCLUSIONS: All six tests distinguished full nonadherence from all other forms of adherence. The rank order of performance was plasma AcSDKP, urine AcSDKP, serum ACE, AII/AI ratio and plasma AII followed by plasma AI.

Aged↗

Planning for major incidents involving children by implementing a Delphi study.

This paper provides a practical approach to the difficult problem of planning for a major incident involving children. It offers guidance on how general principles resulting from an expert Delphi study can be implemented regionally and locally. All phases of the response are covered including preparation, management of the incident, delivery of medical support during the incident, and recovery and support. A check list for regional planners is provided. Supplementary equipment is discussed and action cards for key roles in the paediatric hospital response are shown. Particular emphasis is placed on management of the secondary-tertiary interface including the special roles of paediatric assessment teams and paediatric transfer teams. A paediatric primary triage algorithm is provided. The important role of local interpretation of guidance is emphasised.

Child↗

The relationship between thiopurine methyltransferase activity and genotype in blasts from patients with acute leukemia.

The level of expression of the enzyme thiopurine methyltransferase (TPMT) is an important determinant of the metabolism of thiopurines used in the treatment of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Studies in red blood cells (RBC) have shown that TPMT expression displays genetic polymorphism with 11% of individuals having intermediate and one in 300 undetectable levels. The genetic basis for this polymorphism has now been elucidated and polymerase chain reaction (PCR)-based assays described for the most common mutations accounting for reduced activity. In previous studies, genotype has been correlated with red blood cell activity. In this report, we describe the relationship between genotype and TPMT activity measured directly in the target of drug action, the leukemic cell. We have demonstrated that the TPMT activity in lymphoblasts from 38 children and adults found by PCR to be homozygotes (*1/*1) was significantly higher than that in the five heterozygotes (*1/*3) detected (median, 0.25 v 0.08, P < .002, Mann-Whitney U). Similar results were obtained when results from children were analyzed separately. However, comparison of activity in blasts from AML and ALL showed a higher level in the former (0.35 v 0.22 nU/mg, P < .002, n = 17, 35), suggesting that factors other than genotype may also influence expression.

Acute Disease↗

Why does monitoring fail in jargon aphasia? comprehension, judgment, and therapy evidence.

Many people with jargon aphasia seem unaware of their speech disorder. The first section of this paper reports data from four subjects which indicate that self-monitoring can fail even when subjects' input skills are apparently adequate to detect their errors. Explanations for this dissociation have attributed monitoring failure to a deficit in auditory feedback, or to a resource limitation which prevents concurrent speaking and monitoring. Section 2 reports a series of naming and judging experiments with one of the subjects which rule out these explanations. These show that the subject can detect his neologisms when he is repeating, but not when he is naming. These results suggest that his monitoring difficulties arise when he is accessing phonology from semantics. Section 3 presents a study which supports this inference, since it shows that semantically focused intervention yields improvements in self-monitoring. It is concluded (1) that monitoring failure can arise from deficits within the production process which preclude comparison of actual with intended output, and (2) that this deficit is best explained within a connectionist model in which monitoring is performed by feedback mechanisms in the word production process.

Aged↗

Phonological naming therapy in jargon aphasia: positive but paradoxical effects.

This article is a single-case investigation of phonological naming therapy. The individual involved had fluent jargon speech, with neologisms, verbal paraphasias, and paragrammatisms. The jargon was underpinned by a severe anomia. Content words were rarely accessed either in spontaneous speech or naming. Single word investigations highlighted some preserved skills. Auditory comprehension, at least for concrete words, was relatively intact and although nonwords could not be repeated, words could, and at a level which was far superior to naming. The patient also had some ability to respond to phonological cues. These results suggested that phonological representations were preserved and that there were some intact semantic abilities. It seemed that the naming disorder was primarily due to an inability to access phonology from semantics. Therapy took a phonological approach. The patient was encouraged to reflect upon the syllabic structure and first phoneme of pictured targets. Subsequently, she was required to use this partial phonological knowledge as a self-cue. It was hypothesized that this therapy might equip the subject with a self-cuing naming strategy. Posttherapy investigations of naming demonstrated dramatic improvements, which generalized to untreated items. However, there was little evidence that these were due to a self cuing strategy. Performance on phonological judgment and discrimination assessments, which required conscious phonological reflection, was unchanged, and there were no signs that the patient was self-cuing during naming. Reasons for these paradoxical results are discussed.

Anomia↗

Screening in general practice and primary care.

General practice and its associated primary care services are the final common pathway for the delivery of most screening programmes. The absence of nationally agreed priorities, guidelines and identifiable resources has meant that screening in primary care remains somewhat arbitrary, practice varies widely and programmes remain largely unevaluated. Discussion of screening has focused largely on test characteristics and performance with less attention being given to issues of policy formation, priority setting, implementation and quality assurance. Without these elements, quality and test performance deteriorate, recruitment and follow-up are incomplete and a poorly discriminating test of doubtful utility is applied inequitably and inefficiently. For general practice there are two major concerns. The first is to improve delivery of programmes of proven efficacy, such as breast or cervical screening, that already have a national framework. The second is to develop and provide a national structure for preventive programmes for cardiovascular and smoking-related disease. For cardiovascular disease, the issue is no longer whether to screen and advise whole populations for multiple risk factors, but how best to implement this programme. In this chapter, the case for screening for cardiovascular disease is reviewed and potential strategies for improving delivery of screening in general practice and primary care discussed.

Cardiovascular Diseases↗

Improving uptake of breast screening in multiethnic populations: a randomised controlled trial using practice reception staff to contact non-attenders.

OBJECTIVES: To determine whether a two hour training programme for general practice reception staff could improve uptake in patients who had failed to attend for breast screening, and whether women from different ethnic groups benefited equally. DESIGN: Controlled trial, randomised by general practice. SETTING: Inner London borough of Newham. SUBJECTS: 2064 women aged 50-64 years who had failed to attend for breast screening. Women came from 26 of 37 eligible practices, 31% were white, 17% were Indian, 10% Pakistani, 14% black, 6% Bangladeshi, 1% Chinese, 4% were from other ethnic groups, and in 16% the ethnic group was not reported. MAIN OUTCOME MEASURES: Attendance for breast screening in relation to ethnic group in women who had not taken up their original invitation. RESULTS: Attendance in the intervention group was significantly better than in the control group (9% v 4%). The response was best in Indian women--it was 19% in the intervention group and 5% in the control group. CONCLUSIONS: This simple, low cost intervention improved breast screening rates modestly. Improvement was greatest in Indian women--probably because many practice staff shared their cultural and linguistic background. This intervention could be effective as part of a multifaceted strategy to improve uptake in areas with low rates.

Asia↗

Information needed to decide about cardiovascular treatment in primary care.

There is growing consensus that treatment of cardiovascular risks should be based on multiple rather than single factors and on absolute rather than relative risks. Thresholds for treatment should reflect the level of absolute risk at which the benefits and hazards of treating outweigh the benefits and hazards of not treating. Once a decision has been made to initiate a treatment programme, clinicians need to know the patient's absolute risk. At this level of risk do the benefits of treatment outweigh the hazards? Given this information, which treatment option does the patient prefer? Using cardiovascular disease as an example, I review some measures that assist decision making in primary care. Practice guidelines should routinely include accessible presentation of treatment outcomes on benefit, hazard, and costs for a range of absolute risks. These measures enable patients and their doctors to weigh the pros and cons of treatment in their particular circumstances.

Adult↗

Bacteremia caused by a recently described novel Desulfovibrio species.

An obligately anaerobic, fastidious, slowly growing, spiral, gram-negative bacterium was isolated from the blood of a 75-year-old man with acute onset of pyrexia. The patient responded rapidly to appropriate antibiotic therapy. Extensive investigation failed to detect a focus for the infection. Phenotypically, the organism was consistent with Desulfovibrio species. Microscopic investigation revealed an organism with a vibrioid or spirillioid morphology with rapidly progressive motility by means of a single polar flagellum. Biochemically, the organism produced large amounts of H2S and contained desulfovirdin. The 16S rRNA gene sequence of the organism was found to be most similar to those of members of the genus Desulfovibrio, with identical sequence homology to the newly proposed species described by Tee et al. (W. Tee, M. Dyall-Smith, W. Woods, and D. Eisen, J. Clin. Microbiol. 34:1760-1764, 1996). This is a second unrelated isolation of this novel species from two widely different locations in Australia. The two isolates show some phenotypic differences, indicating that they are different strains of the same species.

Aged↗

Fair shares in health care? Ethnic and socioeconomic influences on recording of preventive care in selected inner London general practices. Healthy Eastenders Project.

OBJECTIVE: To describe the association of ethnic and socioeconomic status with recording of preventive care information by selected general practitioners. DESIGN: Random selection of people aged 20-64 registered with 43 general practitioners. Ethnic and social characteristics of stratified samples were determined at interview in the subject's home. Recording of preventive information was ascertained from general practitioners' medical records. SETTING: Inner London borough of Tower Hamlets. SUBJECTS: 505 ut of 739 people confirmed as residents at their home address (190 white, 86 black, 112 Bangladeshi, 105 Chinese or Vietnamese, 12 other). MAIN OUTCOME MEASURES: Socioeconomic characteristics, consultation with general practitioner, and recorded preventive activities for ethnic groups. RESULTS: Minority ethnic groups were considerably more disadvantaged than white people and five times more likely to be overcrowded (31% v 6%), three times less likely to own their own home(11% v 37%), twice as likely to be in social classes IV and V (54% v 28%) and less likely to be employed (34% v 63%). There were no significant differences between white, black, Bangladeshi, and Chinese or Vietnamese subjects in recording smoking, blood pressure, alcohol consumption, weight, and height in the general practitioners' medical records. White women were more likely to have a record of mammography (46% v 20%; P=0.03) and of cervical smears than women in minority ethnic groups. CONCLUSION: Despite major socioeconomic inequity, equitable recording of preventive activity for the major causes of death for white, black and Bangladeshi populations is possible. Chinese and Vietnamese people had lower levels of recording and consultation. Mammography and, to a lesser extent, cervical cytology are inequitably recorded and require additional support at practice level.

Adult↗