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Biomedical subjects

G O'Sullivan

Publications and source records attributed to G O'Sullivan.

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

Further characterization of the latency-associated transcription unit of Marek's disease virus.

Previous studies have identified a large (L) and a small (S) RNA transcript antisense to the MDV homologue of the ICP4 gene of herpes simplex virus (HSV) in cells infected with Marek's disease virus (MDV) and in lymphoblastoid cell lines. In this study the 5' and 3' ends of the L RNA and of the sense ICP4 transcript of MDV were mapped by Northern hybridization and RNase protection assays. The results showed that L RNA is approximately 10.6 kb and that the ICP4 sense transcript is initiated in the region of genomic DNA where the L RNA terminates whereas L RNA is initiated where the ICP4 transcript terminates. L RNA was abundant in chick embryo fibroblasts (CEF) infected with virus strain HPRS16/attenuated whereas S RNA was predominant in CEF infected with oncogenic HPRS16 and in RPL-1 cell line. Results of cycloheximide experiments showed that the ICP4 gene of MDV was transcribed as an immediate-early gene in infected CEF whereas transcription of the L RNA required protein synthesis. Sequencing of cDNA and Northern hybridization using oligonucleotide probes showed that S RNA shared similar intron/exon boundaries as the cDNAs from several cell lines indicating that there might be a relationship between the S RNA and the antisense transcripts that generated the cDNAs.

Animals↗
PubMed1998

Comparison of three different loading doses to establish epidural analgesia in labour.

Women requesting epidural analgesia were randomized to receive one of three loading doses. Group 1 received a single dose of bupivacaine 9.375 mg (15 ml of 0.0625%) containing fentanyl 37.5 microg and adrenaline 37.5 microg group 2 received a single dose of bupivacaine 15 mg (15 ml of 0.1%) containing fentanyl 30 microg and adrenaline 30 microg and group 3 received a test dose of bupivacaine 10 mg (4 ml of 0.25% - test) followed 5 min later by bupivacaine 20 mg (8 ml of 0.25% - loading). All groups received an infusion of bupivacaine 0.0625% with fentanyl 0.00025% and adrenaline 0.00025% at 10-12 ml/h started 15 min after the loading dose. Speed of onset of analgesia was the same in all three groups, with the majority of women achieving satisfactory analgesia by 20 min. Motor block was significantly increased in group 3 at 30 min, but by 1 h there was no difference in motor block between the groups.

Clinical Trial↗
PubMed1998

What's new in local anaesthetics for obstetric anaesthesia?

Despite its efficacy, bupivacaine has never been considered to be the most suitable agent for achieving anaesthesia and analgesia in the obstetric patient. Ropivacaine is less cardiotoxic than bupivacaine and, at low concentrations, can produce analgesia with minimal motor block, attributes which make it potentially very suitable for use in obstetrics. However, further research is required to ultimately establish ropivacaine's place in obstetric anaesthesia and analgesia. Levobupivacaine, the L isomer of bupivacaine, is of similar potency to bupivacaine but has the advantage of being significantly less cardiotoxic than racemic bupivacaine, which suggests that it might ultimately replace racemic bupivacaine in obstetric practice.

Journal Article↗
PubMed1997

Avascular necrosis of bone following an intensified chemotherapy regimen including high dose steroids.

We report the imaging findings and natural history of avascular necrosis of bone (AVN) that developed following a chemotherapy regimen including high dose steroid treatment. All patients had acute lymphoblastic (ALL) or non-Hodgkin's lymphoma (NHL). Symptoms followed the high dose steroid therapy and 28 joints in eight patients were involved, (11 knees, seven hips, five shoulders and five ankles). Plain radiographs at presentation were normal in most joints, whilst bone scintigraphy and magnetic resonance imaging (MRI) were positive. We believe that the development of AVN in these patients is most likely due to the high dose dexamethasone therapy as in all eight cases symptoms followed this stage of the regimen. Patients experiencing bone or joint pains while receiving high dose steroids as part of a chemotherapy regimen could be investigated by bone scintigraphy but MRI is preferable as it is more sensitive and specific for AVN. In this series of patients multiple joints were involved and all the male patients proceeded rapidly from bone infarction to joint collapse. If the MRI appearances are typical, an early diagnosis of AVN can be made enabling therapeutic interventions to prevent joint collapse and its associated morbidity.

Adolescent↗
PubMed1997

Marek's disease virus EcoRI-Q gene (meq) and a small RNA antisense to ICP4 are abundantly expressed in CD4+ cells and cells carrying a novel lymphoid marker, AV37, in Marek's disease lymphomas.

Mature lymphomas produced in Rhode Island Red (RIR) chickens infected with the RB1B strain of Marek's disease virus (MDV) were examined for the presence of viral DNA and RNA and expression of viral antigens. In situ hybridization showed that all tumours examined contained viral DNA in areas of lymphoid infiltration. In 3/5 tumours, there was a correlation between the number and distribution of cells expressing the Marek's disease EcoRI-Q gene (meq) and those that carried the lymphoid cell marker AV37. Expression of the MDV-specific phosphoprotein pp38 was infrequent in lymphomas but abundant in a splenic tumour which also expressed the viral glycoprotein gB. Northern blot analysis of lymphocyte fractions purified by immunoaffinity showed that CD4+ and AV37+ fractions from lymphomas expressed meq and the small RNA antisense to ICP4 (SAR). The results are consistent with the notion that transformed cells are CD4+ cells, carrying the AV37 marker and expressing meq and SAR.

Animals↗
PubMed1997

Prospective trial of the role of fine bore intubation of the cystic duct at the time of operative cholangiography.

BACKGROUND: The incidence of common bile duct calculi in patients selected for laparoscopic cholecystectomy is 4 to 6 percent. Management is controversial. We report our experience with fine bore cannulation of the cystic duct in patients found on operative cholangiography to have common bile duct stones. STUDY DESIGN: We performed a prospective study of 310 patients who underwent laparoscopic cholecystectomy to evaluate the role of fine bore intubation of the cystic duct at the time of operation. Operative cholangiogrphy was attempted on all patients. In 9 patients, the fine bore tube was left in situ for at least 6 weeks. RESULTS: Intubation was found to be safe and well-tolerated. It permitted biliary decompression and allowed repeat cholangiography. Thirty percent of patients had spontaneous clearance of the common duct stones, which was shown on repeat studies. CONCLUSIONS: Fine bore cannulation of the cystic duct is a safe procedure that allows repeat cholangiography, thus eliminating false-positive results. It reduces the need for intervention by demonstrating the spontaneous disappearance of retained calculi in up to a third of cases.

Cholangiography↗
PubMed1996

Influence of chicken genotype on protection against Marek's disease by a herpesvirus of turkeys recombinant expressing the glycoprotein B (gB) of Marek's disease virus.

Two inbred lines of White Leghorn chickens which differ in B-haplotype were immunized at 2 days of age with a thymidine kinase negative (tk-ve) herpesvirus of turkeys (HVT) recombinant expressing the glycoprotein B (gB) gene of Marek's disease virus (MDV) and were challenged 6 days later with 1000 p.f.u. of the highly virulent RB1B strain of MDV. Mock-vaccinated chickens and chickens immunized with a spontaneous tk-ve HVT mutant served as controls. Genetically resistant B21 chickens were protected by immunization with the recombinant as well as by the tk-ve HVT, whereas highly susceptible B13 chickens were partially protected by the recombinant but were not protected by the tk-ve HVT. Rhode Island Red chickens (HPRS RIR), which differ from the White Leghorns at the B locus, were protected by both vaccines but the recombinant conferred a significantly higher level of protection than the tk-ve HVT. The results suggest that the gB gene of MDV serotype 1 has an important role in the induction of protective immunity against highly virulent MDV in genetically susceptible lines of chickens and that vaccinal immunity in White Leghorns might be influenced by the B haplotype.

Animals↗
PubMed1996

Magnetic resonance imaging in macromelia and macrodactyly.

We report five cases presenting with soft tissue and bone overgrowth that demonstrate the ability of MRI to establish a diagnosis in the absence of specific clinical features. Disorders included macrodystrophia lipomatosa, angiolipomatosis, Klippel-Trenaunay-Weber syndrome, blue rubber bleb naevus syndrome and one case of segmental limited hypertrophy. The MRI appearances, and other radiological features of these conditions are discussed. MRI is recommended in all cases of macrodystrophy when the clinical features and plain film findings are indeterminate.

Adult↗
PubMed1995

Behavioural aggression in panic disorder after 8 weeks' treatment with alprazolam.

23 patients with a diagnosis of panic disorder with agoraphobia were randomly assigned to 8 weeks' treatment with alprazolam or placebo. They filled in self-ratings before and after treatment and competed on a competitive reaction time task, designed to measure behavioural aggression, after 8 weeks' treatment. Patients taking both alprazolam and placebo rated decreased anxiety after 8 weeks' treatment but those on alprazolam also tended to report less hostility. On the behavioural task, patients on alprazolam behaved more aggressively in response to provocation. This is the first study to confirm clinical reports of benzodiazepine-induced dyscontrol on an objective laboratory measure. It is important that it is followed up in a larger group of patients.

Adult↗
PubMed1995

Speed of onset of analgesic effect of intravenous ketorolac compared to morphine and placebo.

The speed of onset of analgesia following intravenous ketorolac, morphine and placebo was investigated in a single-dose, double-blind, randomized, parallel group study of 105 patients. The onset of analgesia was defined as the time at which the pain intensity score reached 50% of the baseline score in 25% of patients. Post-operative patients with moderate or severe pain were dosed and followed for 1 h. Pain reduction by at least 50% occurred in 25% of patients within 40 min (placebo), 15 min (morphine 5 mg), 6 min (morphine 10 mg) and 20 min (ketorolac 10 mg). The pain reduction time for morphine (10 mg) was significantly shorter than that for ketorolac (P = 0.01) or placebo (P < 0.01).

Adult↗
PubMed1994

Pre-treatment predictors of treatment outcome in panic disorder and agoraphobia treated with alprazolam and exposure.

Pre-treatment predictors of treatment outcome were examined in a group of 144 patients with panic disorder and agoraphobia randomly allocated to alprazolam+exposure (AE), placebo+exposure (PE), alprazolam+relaxation (AR), and placebo+relaxation (PR). First-time psychotropic medication use, severity of agoraphobic disability, and longer duration of illness predicted less global improvement at post-treatment. Pre-treatment severity of agoraphobia predicted less improvement both in the short- and the long-term. Predictors of poorer outcome at 6-month follow-up were older age, past history of depression, severity of phobia targets, and longer duration of illness. Sex, source of referral, pre-treatment depression-anxiety-panic, and expectancy from treatment did not relate to outcome.

Adult↗
PubMed1994

Memory functions, alprazolam and exposure therapy: a controlled longitudinal study of agoraphobia with panic disorder.

Benzodiazepines (BZs) produce transient anterograde amnesia when given to normal subjects. The present longitudinal study assessed whether BZs impair memory functions in a clinically anxious group. Eighty-two agoraphobics with panic disorder were randomly allocated to one of four treatment groups resulting from a combination of two drug treatments (alprazolam or placebo) and two psychological treatments (exposure or relaxation). Of these, 38 subjects were assessed on a range of objective and subjective indices of memory and mood at three time points: before treatment, after 8 weeks of treatment and again at 24 weeks when patients had been free of medication from 5-8 weeks. Alprazolam produced pronounced impairments on a word recall task. At the 24-week medication-free follow-up, alprazolam patients were still impaired on the task compared with placebo patients. Alprazolam did not impair performance on an implicit memory task and did not affect digit span. Differences between psychological treatments emerged mainly in subjective memory effects. Findings are discussed in terms of the specificity of BZ-induced amnesia and differential tolerance to the varying effects of BZs. Implications are drawn out for the patient's ability to function optimally in daily life while taking alprazolam.

Adult↗