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Biomedical subjects

I O'Brien

Publications and source records attributed to I O'Brien.

12 recordsLinked to original sources
PubMed2003

Gauze and tape and transparent polyurethane dressings for central venous catheters.

BACKGROUND: Central venous catheters facilitate venous access, allowing the intravenous administration of complex drug treatments, blood products and nutritional support, without the trauma associated with repeated venepuncture. However, central venous catheters are associated with a risk of infection. Some studies have indicated that the type of dressing used for central venous catheters may affect the risk of infection. Gauze and tape or transparent polyurethane film dressings such as Tegaderm, Opsite or Opsite IV3000 are the most common types of dressing used to secure central venous catheters. Currently, it is not clear which type of dressing is the most appropriate. OBJECTIVES: To compare gauze and tape and transparent polyurethane central venous catheter dressings in terms of catheter related infection, catheter security, tolerance to dressing material and dressing condition in hospitalised adults and children. SEARCH STRATEGY: The Cochrane Wounds Group Specialised Trials Register (October 2002), the Cochrane Controlled Trials Register (4th Quarter 2002) and the databases; MEDLINE (1966-December 2002, CINAHL (1982-October 2002) and EMBASE (1980-December 2002) were searched to identify any randomised controlled trials comparing the effects of gauze and tape and/or transparent polyurethane dressings for central venous catheter sites. Additional references were identified from bibliographies of published literature and were also sought from other sources. SELECTION CRITERIA: All randomised controlled trials evaluating the effects of dressing type (i.e. gauze and tape and/or transparent polyurethane dressings) on central venous catheter related infection, catheter security, tolerance to dressing material and dressing condition in hospitalised patients. DATA COLLECTION AND ANALYSIS: Twenty-three studies were reviewed. Data was extracted from each paper by two members of the review team independently and results then compared. Differences were resolved either by consensus or by referral to a third member of the review team. Authors were contacted for missing information. MAIN RESULTS: Of the 23 studies reviewed, 14 were excluded. Nine studies were included. Data was only available for meta-analysis from six of the nine included studies. Of the six included studies with available data, two compared gauze and tape with Opsite IV3000, two compared Opsite with Opsite IV3000, one compared gauze and tape with Tegaderm, and one compared Tegaderm with Opsite. There was no evidence of any difference in the incidence of infectious complications between any of the dressing types compared in this review. Each of these comparisons was based on no more than two studies and all of these studies reported data from a small patient sample. Therefore it is probable that the finding of no difference between dressing types is due to the lack of adequate data. REVIEWER'S CONCLUSIONS: There is a high level of uncertainty regarding the risk of infection with the central venous catheter dressings identified in this review. Therefore, at this stage it appears that the choice of dressing for central venous catheters can be based on patient preference. To identify the most appropriate central venous catheter dressings, further research is necessary. It is paramount that any future studies investigating this issue must be rigorously performed randomised controlled trials.

Bacterial Infections↗
PubMed2000

Isolation of three distinct CycD3 genes expressed during fruit development in tomato.

Tomato (Lycopersicon esculentum Mill.) is an important fruit crop world-wide and a model for studying fruit development. As determined using flow cytometry, fruit growth was characterized by high cell division activity in tomato during the first week after anthesis and followed by endoreduplications (DNA replication without cell divisions). D-type cyclins are considered to be important parts of the signal transduction for stimulation of DNA replication and cell division. To study the function of D cyclins in fruit development, full-length cDNA clones for three D cyclin genes were isolated from young tomato fruit. They were classified as D3 cyclins by sequence similarities and a phylogenetic analysis and named as LeCycD3;1, LeCycD3;2 and LeCycD3;3. The deduced amino acid sequences for LeCycD3;1-3 contained a retinoblastoma-binding motif and a PEST-destruction motif. Pollination and fertilization were followed by a high increase in the transcript levels of LeCycD3;1-3 in young fruit. Using in situ hybridization, high expression of LeCycD3;3 was detected in the vascular tissue of young fruit suggesting a role in vascular development. The D3 cyclins are probably involved in transducing the signals leading to fruit growth by cell divisions. Distinct differences were detected in their temporal and spatial expression patterns suggesting that they play different roles in fruit development as well as in the development of other plant organs.

Amino Acid Sequence↗
PubMed1999

Frontal cortex and the programming of repetitive tapping movements in man: lesion effects and functional neuroimaging.

Two studies examined the contribution of human frontal cortical areas to the programming of trains of repetitive movements. The first study compared the performance of patients with unilateral frontal excisions, unilateral temporal excisions and controls on the speed of initiation of discrete vs. sequential tapping movements to visual stimuli. The frontal group showed normal initiation times in single taps and a normal execution (pace and accuracy) in sequential taps but they were slower than the other groups at initiating sequential taps indicating a sequence programming problem for repetitions of a single response. A second study examined the functional anatomy of single and sequential taps in eight control subjects using fMRI. Subjects performed flexion/extension movements of the right thumb at either 1 movement/s or as trains of four closely spaced movements at a rate of 1 train/4 s. Statistical analyses revealed that primary sensorimotor cortex and a dorsolateral premotor cortex region were activated in both conditions. Medial frontal activation was not significant in discrete movements but was clearly present in sequential movements and involved SMA and cingulate regions bilaterally. In addition, two other dorsolateral premotor foci of activation were observed in the sequential taps condition. Results from these two experiments converge toward establishing a significant role of dorsolateral and medial premotor regions in the programming of trains of repetitive responses.

Adult↗
PubMed1995

Cloning and sequencing of a secY homolog from Streptomyces scabies.

The complete DNA sequence of the Streptomyces scabies (Ss) secY homolog and partial sequences of adjacent upstream and downstream open reading frames (ORFs) have been determined. The nucleotide sequence of a 2-kb region predicts a polypeptide of 437 amino acids in length with homology to the SecY protein family. The Ss secY homolog lies upstream from a sequence that has homology to the adenylate kinase gene (adk) family. The translational stop codon of the putative SecY ORF overlaps the predicted start codon for the Adk ORF. Another ORF that lies upstream from the secY homolog has sequence similarity to the genes that code for the L15 r-protein. Within the 243-bp intergenic region between the L15 and SecY coding sequences, the presence of a streptomycete-like promoter sequence and an 18-bp inverted repeat suggests that the secY homolog and the adjacent downstream sequences may be transcribed independently of the L15 coding sequence. Transcript analysis indicates that the secY homolog is expressed in both Ss and Streptomyces lividans. The proposed gene and transcript organization of the L15-SecY-Adk coding regions in the Ss clone resembles that of Micrococcus luteus which, like the streptomycetes, has a G+C-rich genome.

Adenylate Kinase↗
PubMed1995

The Birmingham pituitary database: auditing the outcome of the treatment of acromegaly.

BACKGROUND: Reduction of GH concentrations in acromegalic subjects may improve the increased mortality associated with the condition. Audit of the biochemical outcome of the management of acromegaly is, therefore, important. OBJECTIVES: (1) To audit the biochemical 'cure' rate of acromegalic patients treated by surgery and/or radiotherapy under the care of the South Birmingham Endocrine Clinic. (2) To assess the correlation between random or basal GH with IGF-I and nadir GH during an oral glucose tolerance test. DESIGN AND MEASUREMENTS: Ascertainment of acromegalic patients from a pituitary database. Mode of therapy, pretreatment GH, pretreatment tumour size, post-treatment GH, post-treatment IGF-I and post-treatment nadir GH were recorded. Biochemical cure was defined as a most recent random or basal GH < 5 mU/l. Cure rates were determined. PATIENTS: Eighty-nine acromegalic patients were identified as having received surgery and/or radiotherapy. In 35/89 (39%) the most recent GH was < 5 mU/l. The cure rate following surgery was 26/78 (33%). This was not significantly associated with tumour size, but was associated with pretreatment GH concentration (chi 2 = 7.1, 2d.f., P < 0.05). Random/basal GH showed a log-linear association with IGF-I, r = 0.72, and a linear association with nadir GH, r = 0.93. CONCLUSIONS: Biochemical cure of acromegaly was more strongly associated with pretreatment GH than with tumour size. Random/basal GH measurements are useful and convenient for the audit of treatment outcome in acromegaly. Ways of improving the biochemical outcome of acromegaly should be sought.

Acromegaly↗
PubMed1985

Oesophageal function in diabetes mellitus and its association with autonomic neuropathy.

We have evaluated oesophageal function in 34 diabetics and in 16 non-diabetic controls by a timed bolus transit method derived from dynamic oesophageal scintiscans (water transit time: WTT) and barium swallow. The diabetics were screened for autonomic neuropathy using standard cardiovascular responses and 10 patients were classified as abnormal. WTT was significantly prolonged in autonomic neuropaths compared with other diabetics (p less than 0.01) and controls (p less than 0.001). Abnormal peristalsis on barium swallow was seen more frequently in autonomic neuropaths (9/10) than in other diabetics (11/24, p less than 0.002). WTTs from all diabetic patients correlated with abnormal heart rate responses at rest (Rs = - 0.49, p less than 0.005), on deep inspiration (Rs = -0.48, p less than 0.005), and on standing (Rs = -0.39, p less than 0.025) but not with the Valsalva manoeuvre. A weaker correlation was found between the postural fall in blood pressure (Rs = 0.3, p less than 0.05). Diabetics with autonomic neuropathy frequently have asymptomatic oesophageal dysfunction which may result from a vagal neuropathy in view of its association with abnormalities of vagally mediated cardiovascular responses.

Adult↗
PubMed1980

Bronchial provocation studies in workers exposed to the fumes of electronic soldering fluxes.

Flux cored solder commonly used in the electronics industry is a metal alloy, based on tin and lead, and a flux consisting of colophony with a small concentration of an activator. Thirty-four electronics workers with occupational asthma and seventeen with respiratory symptoms, probably from other causes, have been investigated by occupational type bronchial provocation testing. All the sensitized workers had a significant fall in FEV1 after exposure to colophony fumes for 15 min or less. The non-sensitized workers had no significant reactivity to this test. There was little correlation between the reaction to colophony fumes and the non specific reactivity to histamine, suggesting that colophony fumes were causing specific sensitization. In sensitized workers Portuguese Y colophony was found to cause slightly larger reactions than similar exposures to American WW colophony. In the six workers tested reactions followed exposure to abietic acid alone, the principal resin acid in colophony. Methylation of the carboxyl group of colophony was associated with decreased reactivity. Workers with non-specific bronchial hyperreactivity also sometimes reacted after exposure to fumes from the flux activators alone, but even this reaction could show specificity for the specific activator to which the workers was exposed. Finally two non-colophony substitute materials were evaluated.

Abietanes↗
PubMed1979

Blood histamine levels after exercise testing.

Histamine has been measured in whole blood and in the plasma of twenty-three subjects following exercise testing of seventeen asthmatics and six normal controls. Whole blood histamine rose in both asthmatics and controls and was associated with a concomitant rise in the basophil count. Plasma histamine in the peripheral venous blood only rose in one patient who developed urticaria after exercise.

Asthma↗