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Biomedical subjects

I Barker

Publications and source records attributed to I Barker.

At least 37 records · Page 2Linked to original sources
PubMed1998

Strain specific recombinant antibodies to potato virus Y potyvirus.

Single chain Fv antibody fragments have been selected from a synthetic phage-antibody library following three and four rounds of affinity selection with purified potato virus Y, common strain (PVY(O)). The selected fragments were highly specific for PVY and detected seven out of nine isolates of PVY(O) whilst failing to detect three isolates of PVY(N) and 12 isolates of PVY(NTN). Nucleotide sequence of the scFv genes showed the variable heavy fragments belonged to the human VH4 family, whilst the variable light fragments belonged to the Vlambda1 family. The fragments were used in ELISA to detect virus at concentrations of 50 ng/ml in plant sap and in comparisons with commercially available PVY monoclonal antibodies were shown to have similar limits of detection. This is the first report of the selection of a scFv specific for a member of the potyviridae, and its use in detecting and differentiating strains of PVY in infected plant sap. The results highlight the potential of the technology for the selection of strain specific antibodies with an avidity equivalent to traditional monoclonal antibodies raised against viral pathogens and their use for viral diagnosis.

Amino Acid Sequence↗
PubMed1998

Anaesthetic management of a child with Burkitt's lymphoma of the larynx.

An eight-year-old boy with a Burkitt's lymphoma of the upper airway is described. The use of sevoflurane for induction of anaesthesia in patients with airway obstruction is discussed. The logistical problems of upper airway surgery and anaesthesia in this type of patient are considered.

Anesthesia, Inhalation↗
PubMed1998

Anaesthetic training programmes in the UK: the role of the programme director.

Schools of anaesthesia provide anaesthetic training in the UK. Each school has at least one programme director undertaking some or all of the management duties. Most programme directors appears to be unresourced volunteers whose roles have developed in response to local requirements. A postal questionnaire was sent to all anaesthetic training programme directors in the UK, asking about their role. Respondents had a wide variation in duties and responsibilities towards anaesthetic training schemes. Few had terms of reference, clear lines of responsibility, remuneration or resources to undertake the role.

Anesthesiology↗
PubMed1997

Propofol infusion vs thiopentone/isoflurane anaesthesia for prominent ear correction in children.

Postoperative nausea and vomiting (PONV) frequently follows prominent ear correction under general anaesthesia in children. In a prospective, single-blind study, we compared the incidence of PONV after propofol infusion anaesthesia with that following thiopentone induction and isoflurane maintenance in 30 children aged from four to 14 years randomly allocated to one of two groups. All the children were mechanically ventilated. Anaesthesia was supplemented in both groups with nitrous oxide and infiltration of the ears using a mixture of bupivacaine, adrenaline, and hyaluronidase. One child receiving propofol (group P) complained of nausea, compared with eight receiving thiopentone/ isoflurane, (group T) (P = 0.005), while three children in group P and ten in group T vomited before hospital discharge, (P = 0.01). Eight children in group P were considered to be fit for discharge on the day of surgery as against four in group T, (not significant). Only four out of twelve children receiving opioid analgesia vomited.

Adolescent↗
PubMed1997

A comparison of thiopentone-isoflurane anaesthesia vs propofol infusion in children having repeat minor haematological procedures.

We have performed a randomized, cross over study in 22 children suffering from acute leukaemia, who underwent repeated anaesthesia for bone marrow aspiration and lumbar puncture. For their first anaesthetic, the children (aged 3-10 years old) received, either a thiopentone/isoflurane anaesthetic or intravenous propofol, both supplemented with nitrous oxide. On a second occasion they received the alternative technique. Of those children receiving thiopentone/isoflurane, 32% had significant coughing during anaesthesia, two progressing to laryngospasm requiring 100% oxygen. None of the patients receiving propofol had a respiratory disturbance (P = 0.016). 68% of the children preferred the propofol anaesthetic. Only one child in the thiopentone/isoflurane group preferred this technique. Twenty-seven per cent had no preference. There was no significant difference in length of anaesthetic time (P = 0.07) or the time taken for recovery (P = 0.17) between the two groups. There was a large individual variation in propofol requirements and movement was common during stimulation of patients in this group, though this did not adversely affect the surgical procedure.

Acute Disease↗
PubMed1996

Improved detection of barley yellow dwarf virus in single aphids using RT-PCR.

The detection of a British isolate of barley yellow dwarf virus (BYDV-G, PAV-like) from individual vector aphids, using a combined assay of reverse transcription and polymerase chain reaction (RT-PCR) is reported. The method makes use of a multiplex format, including internal control primers directed at conserved regions of insect actin. The actin primers serve as controls for each stage of the method and are suitable for use in a range of invertebrate species. Detection of BYDV in vector aphids for use in forecasting systems is at present carried out using an enzyme-amplified ELISA system. In direct comparisons with the amplified ELISA, RT-PCR shows an increase in sensitivity detecting 11 fg of purified virus. Detection of virus in ELISA-negative aphids by RT-PCR was also demonstrated, and its potential as a routine diagnostic tool for virus detection in aphids is discussed.

Animals↗
PubMed1996

An improved method for the detection of Tospoviruses using the polymerase chain reaction.

A reverse transcription-polymerase chain reaction (RT-PCR)-based assay for the detection of tomato spotted wilt virus (TSWV) has been improved and extended to enable the detection of additional Tospoviruses. In addition to TSWV-specific primers, two further pairs of primers have been designed, one pair which specifically detects impatiens necrotic spot virus (INSV) and another which detects all Tospoviruses tested, including TSWV, INSV, tomato chlorotic spot virus and groundnut ringspot virus. An improved, rapid RNA extraction method is also described.

Base Sequence↗
PubMed1996

Leg ischaemia in an infant following accidental intra-arterial administration of atracurium treated with caudal anaesthesia.

We describe the effects of accidental intra-arterial injection of suxamethonium and atracurium into the femoral artery of an infant. An 11-month-old boy with Downs Syndrome and obstructive sleep apnoea presented for tonsillectomy. Peripheral venous cannulation proved impossible. A femoral venous line was sited following inhalational induction of anaesthesia. Suxamethonium was given through this line and produced no adverse effect. Subsequently, atracurium was given through the line causing an instant cutaneous flush in the leg followed by a marked ischaemic appearance. The femoral line was assumed to be sited in the femoral artery and was removed. At the end of the operation a caudal injection of 10 ml of 0.25% bupivacaine was performed. Within 30 min there was marked vasodilation of both legs with easily felt peripheral pulses. In view of the tonsillectomy anticoagulant and thrombolytic therapy were contra-indicated. There were no adverse sequelae.

Anesthesia, Caudal↗
PubMed1995

Detection of beet necrotic yellow vein virus using reverse transcription and polymerase chain reaction.

A diagnostic test based on reverse transcription followed by the polymerase chain reaction (RT-PCR) was developed for the detection of beet necrotic yellow vein virus (BNYVV). A specific 500-base-pair fragment was amplified from the read-through region of the coat protein gene located on RNA-2. The viral origin of the amplified product was confirmed by sequencing, with the sequence obtained having 94.5% homology with published sequence data for BNYVV. The assay gave a sensitivity of 800 times that of a TAS-ELISA and 50 times that of an amplified TAS-ELISA method. A range of BNYVV isolates from the UK and worldwide could be detected by this test, either as mechanically inoculated Chenopodium quinoa leaves or infected sugar beet roots. Use of the assay in routine diagnostic tests allowed a reduction of time needed for the detection of Rhizomania in soils from 7 to 4 weeks.

Base Sequence↗
PubMed1994

The detection of tomato spotted wilt virus using the polymerase chain reaction.

A polymerase chain reaction (PCR) based assay was used to detected a number of UK tomato spotted wilt virus (TSWV) isolates in total RNA extractions made from infected plant material. Extracts were reverse transcribed and the resultant cDNA amplified by PCR, using oligonucleotide primers specific for a 276 base pair fragment of the L RNA segment. Assay products were electrophoresed on agarose gels and visualised by ethidium bromide staining. The viral origin of the product produced was confirmed by sequencing, with the data obtained having very high homology with previously published L RNA sequence data. The specificity and sensitivity of the RT-PCR assay, in comparison with existing tests, is discussed.

Base Sequence↗
PubMed1994

Parents in the anaesthetic room--parents' and anaesthetists' views.

In this study parents' and anaesthetists' views were compared, by means of questionnaire, to assess the benefit of parental presence at induction. One hundred and ninety four unpremedicated children aged 1-16 years underwent daycase surgery. One hundred and eighty four parents accompanied their child and felt that their child benefited from this. Anaesthetists rated only 72% of parents as being helpful. Parents who had undergone anaesthesia in the past were less likely, 60% compared with 79% (p < 0.01), to consider themselves as upset than parents who had not. Thirty one percent (44/140) of anaesthetists, compared with 43% (60/140) of parents, felt the child was upset at induction (p < 0.01). Parents judging themselves to be upset at induction were significantly more likely to consider their child as upset (p < 0.01). Most parents feel that they are of help in the anaesthetic room regardless of whether or not they find it an upsetting experience. Ninety eight per cent would want to accompany their child in the future and we believe this should be allowed unless there are overriding considerations.

Adolescent↗