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Biomedical subjects

S E Bailey

Publications and source records attributed to S E Bailey.

10 recordsLinked to original sources
PubMed2000

Prostate cancer: the role of transrectal ultrasound and its impact on cancer detection and management.

With the advent of higher-frequency transducers as well as Doppler technologies, TRUS has become a valuable tool in the detection and management of prostate cancer. When combined with the other risk identifiers, an informed patient, and an experienced operator, it cannot only reduce the number of missed cancers by effective targeting of biopsies, but also reduce the number of unnecessary biopsies.

Biopsy↗
PubMed2000

Premature ventricular contractions during triggered imaging with ultrasound contrast.

BACKGROUND: Premature ventricular contractions (PVCs) were observed during triggered second harmonic imaging of a contrast agent for myocardial perfusion assessment, with continuous infusion of the contrast agent. Further investigation into the relation of this phenomenon to both ultrasound energy and the contrast agent was carried out during a subsequent bolus-versus-infusion study. METHODS AND RESULTS: Two open-label studies in healthy male volunteers were performed. The initial study was a dose-response study in 10 subjects, which compared 3 infusion rates. Each volunteer received 3 continuous infusions with different infusion rates of the contrast agent for either 10 (n = 6) or 20 (n = 4) minutes. End-systolic triggered imaging with a mechanical index (MI) of 1.5 was used throughout this part of the study. The second study compared bolus injection with a continuous infusion in 9 volunteers, with a single-dose level but different imaging modalities: end-systolic and end-diastolic triggered imaging at MIs of both 1.1 and 1.5. Spontaneous baseline PVCs were uncommon: 10 in 344 minutes (0.03 PVC/min, maximal 1 PVC/min) of baseline imaging. During end-diastolic triggering, no increase in PVCs was seen, irrespective of MI. A significant increase to 1.06 PVC/min (P <.001) was seen during end-systolic imaging with an MI of 1.5, but not with an MI of 1.1. The increase in PVC rate was dose-dependent in the initial study. CONCLUSION: Imaging of contrast agents with high acoustic pressures can cause PVCs if end-systolic triggering is used. This effect is related to both the dose of contrast agent and acoustic pressure. It does not occur during end-diastolic triggered imaging. Precautionary measures would include using lower MIs or end-diastolic triggering.

Adult↗
PubMed1998

When believing is seeing: the effect of scripts on eyewitness memory.

Two studies examined the conditions under which event schema or scripts produce gap-filling errors in eyewitness accounts of a robbery. In Study 1, scripts for the robbery of a convenience store were identified. Results revealed high agreement among the 120 participants concerning the sequence of actions for such a robbery. Based on the information obtained in Study 1, participants in Study 2 (N = 144) viewed one of two sequences of slides depicting a robbery of a convenience store by a lone robber. In one sequence, three central script actions were omitted and in the other, three peripheral script actions were omitted. In addition, rate of exposure was varied (2 vs. 8 sec) as was the length of the retention interval (5 min vs. 1 week). As predicted, there was a higher rate of false recognition for central as opposed to peripheral actions, and this tendency was exaggerated for the longer retention interval. The theoretical and practical implications of the findings are discussed.

Adult↗
PubMed1997

Human biodistribution of an ultrasound contrast agent (Quantison) by radiolabelling and gamma scintigraphy.

The biodistribution and kinetics of an air filled human serum albumin microcapsule formulation (Quantison) intended for use as an intravenous ultrasound contrast agent have been examined. 12 healthy subjects were administered with approximately 50 million microcapsules per kilogram body weight, radiolabelled with 50 MBq 123I. Imaging was performed over a period of 58 h using a large field-of-view gamma camera and the amount of labelled material present in the blood, urine and faeces measured. Imaging demonstrated that the liver was the organ with the highest uptake, with a mean uptake of 41.8% (SD 10.4%) of the administered dose 1 h following administration. The maximum uptake of the agent in the lungs was low, mean 4.0% (SD 3.4%). A small amount of uptake was visible in the bone marrow; however, this was not quantifiable. There was also evidence of minimal myocardial activity within 5 min of administration. No adverse events were observed and there were no changes in any of the individual post-study indices. The present study demonstrates the safety of Quantison. Gamma scintigraphy played a useful role in confirming the biodistribution of the agent with little lung uptake, high liver uptake and evidence of myocardial uptake.

Adult↗
PubMed1995

The use of DNA markers in the pre-clinical diagnosis of familial adenomatous polyposis in families in South Africa.

Haplotype association studies were performed in 10 unrelated South African families and 1 German immigrant family with familial adenomatous polyposis (FAP). Three DNA probes, recognising five restriction fragment length polymorphisms (RFLPs) around the gene locus for FAP on chromosome 5q, were used. The RFLP analysis was informative or partially informative in all the families studied. Five haplotypes were found to segregate with the disease locus. The predominant association of two of these haplotypes with FAP in the South African families suggests that two mutations may cause the disease in about 70% of families in this population. Meiotic recombination events were detected between the FAP gene and probe M4 (D5S6), but not probes Pi227 (D5S37) and C11p11 (D5S71). Haplotype analysis allowed the preclinical diagnosis of FAP in 5 subjects.

Adenomatous Polyposis Coli↗
PubMed1995

Inhibition of feeding responses by the molluscicide, metaldehyde.

Metaldehyde, applied to the lips, inhibits spontaneous biting movements and disrupts rhythmic feeding motor output. Applied directly to the CNS, it induces a region of negetive slope conductance in the steady-state I-V curve, which could contribute towards generation of convulsant activity. Isolated muscle tissue (buccal mess, gut and foot) shows increased frequency and amplitude of contractions when exposed to metaldehyde. All these actions contribute towards the disruption of feeding behaviour.

Acetaldehyde↗
PubMed1993

Urine and the laboratory diagnosis of Chlamydia trachomatis in males.

OBJECTIVE: To determine whether the use of urine samples from male patients can replace urethral swabs for the rapid detection of Chlamydia trachomatis by the Pharmacia EIA. SETTING: The STD clinic, Adelaide, South Australia. PATIENTS: There were two separate groups of male patients. Group A (398) patients provided urethral specimens for the EIA and culture tests. The patients in Group B (356) provided an urethral swab and a urine sample for the EIA test. METHODS: The urine samples and urethral swabs were tested for the presence of C trachomatis by the Pharmacia Chlamydia EIA. In addition, the urethral swabs from Group A patients were cultured for the organism by standard cell cultures. The infected cell cultures were identified by an immunofluorescence test using a FITC-monoclonal antibody to C trachomatis (Kallestad). RESULTS: When the EIA was validated against culture, it showed a sensitivity of 100% and a specificity of 95% with the urethral swabs from Group A patients. The urine specimens were positive in 24% of those patients who yielded a positive EIA result in the urethral swabs. CONCLUSIONS: Although the EIA test on urethral swabs showed high sensitivity and specificity when validated against culture, our results showed that the use of urine samples cannot replace urethral swabs for the laboratory diagnosis of this sexually transmitted disease.

Adult↗
PubMed1992

Accumulation and excretion of aluminium and iron by the terrestrial snail Helix aspersa.

1. The snail Helix aspersa was fed one 24 hr meal containing Al, Fe or both together in barley flour pellets. Accumulation and distribution within the digestive gland, kidney, crop and remaining soft tissues were examined over the subsequent 30 days using atomic absorption spectroscopy (A.A.S.). 2. The digestive gland contained significantly (P < 0.05) elevated levels of Al and Fe for 8 and 12 days. The digestive gland is the major sink for both Al and Fe in Helix. 3. The kidney rapidly accumulated Al and Fe but the increase was short-lived. The kidney may therefore be involved in the elimination of metal not incorporated into the digestive gland. 4. Iron was absorbed by the crop but Al was not. This may indicate a route of uptake of Fe into the digestive gland not shared with Al. 5. No obvious pattern of accumulation of Al and Fe were seen in the remaining soft tissues or the blood of Helix. 6. Aluminium is present in the faeces for 12 days suggesting that Al is released relatively slowly. 7. Presence of both Al and Fe in the feed induced a change in the pattern of accumulation in the digestive gland but not in the kidney, crop and remaining soft tissues. 8. The distribution of Al is discussed in relation to the suggestion that Al follows the ferretin pathway during accumulation.

Aluminum↗
PubMed1990

Serological analysis of duck hepatitis B virus infection.

A radioimmunoassay was developed to detect duck hepatitis B virus surface antigen and antibody; viraemia (DHBV DNA or DHBsAg) was detected in all ducks inoculated within 3 weeks post-hatch, and persistent infection developed in 93% of birds in this group. In contrast, only 80% and 60% of ducks inoculated 4- and 6-weeks post-hatch respectively developed viraemia, and approximately 70% of the viraemic ducks became carriers. Markers of viraemia were undetected in ducks inoculated 8 weeks post-hatch and in uninfected controls. A typical anti-DHBs seroconversion developed subsequently in 2 of 4 birds that showed transient viraemia, and antibody also developed in 3 of 7 ducks inoculated 4-8 weeks post-hatch that showed no viraemia. However, gene amplification by the polymerase chain reaction demonstrated DHBV DNA in ducks from the latter group suggesting that the antibody did not result from passive vaccination. Thus, increased resistance to infection develops with increasing age that may be related to several factors including host immunity. This model may help elucidate similar age-related features of human hepatitis B virus infections.

Animals↗