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Biomedical subjects

J Gray

Publications and source records attributed to J Gray.

At least 181 records · Page 10Linked to original sources

The development of a specimen exchange system for quality assessment of polymerase chain reaction tests.

A programme of external quality assessment of polymerase chain reaction (PCR) assays through regular exchange of appropriate clinical or spiked specimens between Oxford and Cambridge public health laboratories began in February 1997. We report on 60 specimens included in the exchange. These covered most of the molecular diagnostic assays in use at present. In two cases discrepant results were obtained. We conclude that the exchange of specimens under code between laboratories that use molecular techniques as a diagnostic service is an inexpensive way of achieving regular external quality assessment.

Humans↗

An outbreak of Salmonella agona infection associated with precooked turkey meat.

An outbreak of Salmonella agona phage type (PT) 15 infection in North Staffordshire in September 1996 was associated with consumption of precooked turkey meat. The shops from which five of the six cases had bought turkey meat were supplied by the same distributor. S. agona phage type 15 was isolated from nine cases, from cooked turkey sampled from a shop, and from an unopened cryovacuumed packed joint at the supplier's premises. Environmental investigations at a food manufacturer's premises revealed deficiencies in cooking practices. Microbiological investigations at those premises on samples (food, environmental swabs) taken two to three weeks after the cases became ill were negative. The rarity of S. agona brought this outbreak to our attention and the successful identification of a vehicle of infection demonstrated the value of local surveillance of gastrointestinal pathogens and of good working relationships between public health and local authority staff. The prompt voluntary withdrawal of suspect product probably prevented further cases.

Adult↗

Baby CareLink: development and implementation of a WWW-based system for neonatal home telemedicine.

Baby CareLink is a multifaceted telemedicine application designed to provide individualized information and support to families of Very Low Birth Weight infants. We believe that this innovative use of WWW and telemedicine technologies will improve family satisfaction and clinical care. In conjunction with improvements in family involvement, discharge planning, education, and follow-up enabled by other CareLink components, this system may allow infants to transition home even earlier in their hospital stay and thereby provide a clear cost savings. This paper discusses the CareLink architecture and lessons learned in implementing a telemedicine link with families at home from an in-hospital clinical unit.

Computer Security↗

Subregional localization of 21 chromosome 7-specific expressed sequence tags (ESTs) by FISH using newly identified YACs and P1s.

Twenty-one putative chromosome 7-derived expressed sequence tags (ESTs) identified 33 yeast artificial chromosomes (YACs) or P1 clones, which were then used as reagents for physical mapping. FISH mapping established that the ESTs contained within these clones were distributed throughout chromosome 7, with all major cytogenetic bands represented, except 7p13-p15, 7p11, 7q31.2, and 7q35. Each EST sequence identified at least one other sequence in publicly available databases (using search tools such as BLASTN, basic local alignment search tool), and many of the ESTs identified cDNAs and several genomic DNA sequences. However, 7 ESTs did not identify highly significant matches (P < 1 x 10(-5)). Only one (EST01924-D7S2281E) failed to identify any other EST from the dbEST homology searches. BLAST analysis identified at least five genes from EST sequence comparisons: protein tyrosine phosphatase zeta (PTPRZ, also known as RPTPZ) (EST02092), which we had mapped to 7q31.3, in agreement with previous studies; cAMP-dependent protein kinase regulatory subunit bI (EST01644); rat integral membrane glycoprotein (EST00085); human IFNAR gene for interferon alpha/beta receptor (EST00817); and rat 14-3.3 protein gamma subtype (putative protein kinase C regulatory protein) (EST00762). These ESTs will help to develop the map of chromosome 7, which integrates physical, transcriptional, and cytogenetic data, as well as to provide candidate disease genes for chromosome 7-specific disorders.

Animals↗

FISH probes for mouse chromosome identification.

P1 clones near the telomeres and centromeres of each mouse chromosome except Y have been selected from a mouse genomic library and mapped using fluorescence in situ hybridization (FISH). Each clone was selected to contain a genetically mapped polymorphic DNA sequence as close as possible to the centromere or telomere of a chromosome. The genetic distance from the various P1 clones to the most distal genetically mapped polymorphic sequence ranged from 0 for about half of the clones to 6.7 cM for the probe at the telomere of chromosome 14. The average distance to the most distal or proximal chromosome marker was 1.5 cM. The use of FISH with these probes for mouse chromosome identification during comparative genomic hybridization is illustrated.

Animals↗

Effect of cognitive-behavioural training on job-finding among long-term unemployed people.

BACKGROUND: The principles of cognitive-behavioural therapy (CBT) have been applied successfully through individual psychotherapy to several psychiatric disorders. We adapted these principles to create a group--training programme for a non-psychiatric group-long-term (> 12 months) unemployed people. The aim was to investigate the effects of the programme on measures of mental health, job-seeking, and job-finding. METHODS: 289 volunteers (of standard occupational classification professional groups) were randomly assigned to a CBT or control programme, matched for all variables other than specific content, that emphasised social support. 244 (134 CBT, 110 control) people started the programmes and 199 (109 CBT, 90 control) completed the whole 7 weeks of weekly 3 h sessions (including three CBT, seven control participants who withdrew because they obtained employment or full-time training). Questionnaires completed before training, on completion, and 3-4 months later (follow-up data available for 94 CBT, 89 control) assessed mental health, job-seeking activities, and success in job-finding. Analyses were based on those who completed the programmes. Participants were not aware that two interventions were being used. Investigators were aware of group allocation, but were accompanied in all programmes by co-trainers who were non-investigators. FINDINGS: Before training, 80 (59%) CBT-group participants and 59 (54%) controls scored 5 or more on the general health questionnaire (GHQ; taken to define psychiatric caseness). After training, 29 (21%) and 25 (23%), respectively, scored 5 or more (p < 0.001 for both decreases). Improvements in mean scores with training on the GHQ (between-group difference 3.91, p = 0.05) and in other measures of mental health were significantly greater in the CBT group than in the control group. There were no significant differences between the groups in job-seeking activity during or after training, but significantly more of the CBT group than of the control group had been successful in finding full-time work (38 [34%] vs 13 [13%], p < 0.001), by 4 months after completion of training. INTERPRETATION: These results suggest that group CBT training can improve mental health and produce tangible benefits in job-finding. Application of CBT among the unemployed is likely to benefit both individuals and society in general.

Adult↗

A novel suppressor of cell death in plants encoded by the Lls1 gene of maize.

The Lls1 (lethal leaf spot1) locus of maize is defined by a recessive mutation characterized by the initiation, in a developmentally programmed manner, of necrotic lesions that expand to kill leaves cell autonomously. The loss-of-function nature of all Lls1 mutants implies that the Lls1 gene is required to limit the spread of cell death in mature leaves. We have cloned the Lls1 gene by tagging with Mutator, a transposable element system in maize, and we show that it encodes a novel protein highly conserved in plants. Two consensus binding motifs of aromatic ring-hydroxylating dioxygenases are present in the predicted LLS1 protein, suggesting that it may function to degrade a phenolic mediator of cell death.

Amino Acid Sequence↗

Individual differences in auditory middle latency responses in elderly adults and patients with Alzheimer's disease.

Previous research has suggested that the Pb component of the middle-latency auditory evoked response (MLAER) is differentially abnormal in patients with Alzheimer's disease relative to control subjects. In the present study, this putative abnormality was examined in vertex-recorded MLAERs elicited by monaural stimulation in 14 patients with Alzheimer's disease (six females) and 22 age-matched control subjects (10 females). A sex difference in Pb elicitation was revealed in control subjects; Pb area was twice as large in females than males (P < 0.05). Pb and Pa amplitudes and latencies did not differ between male and female control subjects. Comparisons of Pb between patients and controls were conducted within each sex. There was no main effect of group on Pb area, amplitude, or latency, Pa amplitude was significantly larger in patients than control subjects; there was no group difference in Pa latency. This study did not replicate previous reports of differences in Pb between patients with Alzheimer's disease and elderly control subjects. We demonstrated that Pb elicitation may be unreliable in elderly control subjects and found evidence of a possible sex difference. The effects of inter-subject variables (e.g. age, sex) must be understood more fully before MLAERs can be exploited as meaningful markers of brain dysfunction.

Acoustic Stimulation↗

HIV in the neonate.

Mother-to-infant transmission of human immunodeficiency virus (HIV) is a worldwide problem. Between 7 and 40% of infants born to HIV-positive mothers become infected. The prognosis of these infants is poor, with most developing early and rapidly progressive disease. A number of advances in diagnosis and therapy offer opportunities to reduce the rate of vertical transmission and to improve the outlook of infected infants. Antiretroviral therapy during pregnancy and the neonatal period can markedly reduce the risk of mother-to-infant transmission. Recognition that 50% or more of infections are transmitted peripartum offers scope to further reduce the rate of transmission. However there is currently no consensus on the optimal management of pregnancy in HIV-infected women, and there is an urgent need for large randomized controlled trials. The development of polymerase chain reaction and p24 antigen assays has greatly facilitated the diagnosis of neonatal HIV infection, thereby enabling earlier supportive and anti-retroviral therapy. The place of zidovudine in paediatric HIV infection is now well-established, but the future will undoubtedly bring combination anti-retroviral therapy. Optimism about the prospects for developments in the prevention and treatment of paediatric acquired immunodeficiency syndrome must be tempered by the fact that the majority of cases occur in countries where patients have little or no access to medical care.

AIDS-Related Opportunistic Infections↗

In vivo binding and hearing loss after intracochlear infusion of KHRI-3 antibody.

The IgG1 mouse monoclonal antibody (MAb) KHRI-3, binds to an antigen of 65-68 kDa expressed on inner ear supporting cells in guinea pigs. We previously showed [Nair et al. (1995) Monoclonal antibody induced hearing loss. Hear. Res. 83, 101-113] that mice carrying the KHRI-3 hybridoma develop high frequency hearing loss and loss of hair cells in the basal turn suggesting that this MAb causes immune-mediated sensorineural hearing loss. To evaluate the specificity of this effect, sterile KHRI-3 and control IgG1 preparations were infused directly into the guinea pig cochlea using Alzet mini-osmotic pumps. Assessments included: (1) hearing, measured by click auditory brain stem responses (ABRs); (2) in vivo antibody binding; and (3) the structural integrity of the organ of Corti. Nine animals were infused with KHRI-3 preparations and 5 controls were infused with control IgG1. Four guinea pigs given KHRI-3 developed 25-55 dB hearing loss. Control animals showed no difference from baseline. In vivo binding of KHRI-3 was detected in the organ of Corti in 6 of the 9 animals, including all 4 that had hearing loss. No staining was observed with control antibody. Confocal microscopy revealed that the in vivo KHRI-3 antibody binding pattern was identical to that obtained by incubating fixed tissue in vitro with KHRI-3. Histologic examination revealed an increased frequency of hair cell loss in KHRI-3 treated ears when compared to either the contralateral ears of the same guinea pigs or the IgG1 treated ears of control animals. The lesions in the infused ears of guinea pigs were scattered throughout the cochlea from base to apex. These experiments demonstrate the following points: (1) Antibodies can be chronically infused directly into the cochlea of living animals. (2) The KHRI-3 antibody binds to live supporting cells within the organ of Corti. (3) Infusion of an inner ear specific antibody affects auditory function. (4) The infusion of irrelevant antibody had no effect on the structure or function of the ear. This system provides an animal model for further studies of antibody-induced sensorineural hearing loss.

Animals↗