Biomedical subjects

John Anderson

Publications and source records attributed to John Anderson.

42 records · Page 3Linked to original sources

PubMed2003

Cultural meanings of nature: an analysis of contemporary motion pictures.

To evaluate current cultural meanings of nature, the authors asked 65 undergraduate students to "list 3 movies in which nature was an important aspect of the film." They also were asked to specify the natural element that stood out to them and describe "how it related to the overall theme of the movie." Two independent groups of raters skilled in interpretive analysis developed thematic meanings from these responses. Following this, in a 2nd study, a different group of participants rated the 18 most frequently mentioned natural elements on thematic scales derived from the initial interpretive analysis. Participants in the 1st study mentioned 33 different movies at least twice and 5 themes that captured the meaning of nature in these films. Correlational results derived from the 2nd study indicated that rating scales reflecting these 5 themes formed 2 distinct groups; the first group described settings in which nature is experienced as adversarial and plays a significant role in dramatic action, and the second group defined settings in which nature is viewed either as a place of refuge or simply as a locale in which ongoing narrative action occurs. The general conclusion reached in both studies concerns the often noted but not always appreciated fact that movies--similar to everyday events and actions--always take place in specific settings and that neither life events nor dramatic narratives can be understood apart from specific settings.

Adolescent↗

PubMed2002

Australian audit for the endoluminal repair of abdominal aortic aneurysm: the first 12 months.

BACKGROUND: The Australian Safety and Efficacy Register for New Interventional Procedures - Surgical (ASERNIP-S) was contracted by the Commonwealth Department of Health and Aged Care to audit the procedure of endoluminal repair of abdominal aortic aneurysm. The purpose of the audit was to examine the safety and efficacy of the endoluminal graft (ELG) and, where possible, compare it to the open procedure. The first 12 months of data collection has now been completed. An overview of these results and some of the problems associated with the establishment of this audit are given. METHODS: The administrative infrastructure to support the audit is based at the ASERNIP-S office in Adelaide. To achieve high compliance rates, regular contact was maintained with surgeons. A reference group of senior vascular surgeons was established to provide expert support to the audit. RESULTS: By December 2000, ASERNIP-S had collected data on approximately 85% of privately performed ELG procedures during the first year of the audit. The early mortality rate was 1.3% in the endoluminal group compared to 2.6% in the open group. The rate of procedural complications was 15% in both groups, but the percentage of systemic complications was higher following the open repair. Aneurysm size and the number of pre-existing conditions had a statistically significant relationship to the variation in the number of complications for ELG patients. CONCLUSIONS: Good compliance has been obtained from vascular surgeons for submission of the operative data sets. ASERNIP-S aims to follow this group of patients closely to assess the medium to long-term durability of this procedure.

Aged↗

PubMed2002

Optimization of transthoracic ventricular defibrillation-biphasic and triphasic shocks, waveform rounding, and synchronized shock delivery.

The aim of this study is to optimize the truncated exponential waveform for transthoracic ventricular defibrillation. Discharge of a capacitor gives a fast-rising waveform with a spike; rounding of the waveform slows the rate of rise and removes the spike. Defibrillation thresholds for electrically induced VF were determined for rounded and conventional biphasic and triphasic waveforms (apex-anterior paddles; 130 microF capacitor; 3-10 ms phase duration), and for the Lown waveform in 29 anesthetized pigs. Rounding of the leading edge of the biphasic waveform reduced the threshold voltage and current for defibrillation at 3 + 3 ms and 6 + 6 ms phase duration, relative to the conventional unrounded biphasic or the Lown waveforms. The threshold delivered energy was lower for rounded truncated exponential biphasic shocks at 3 + 3 ms (55.3 +/- 2.5 J) than at 6 + 6 ms (67.6 +/- 2.9 J; reduction 15.9 +/- 3.8%; P <.001; n = 29) phase duration. Triphasic shocks (total duration 6-12 ms) showed no advantages over biphasic shocks in this model. The rounded waveform (6 + 6 ms phase duration) had a reduced delivered energy at threshold (9%) with transthoracic shock delivery synchronized to peak (71.1 +/- 4.2 J) or trough (71.5 +/- 4.9 J) of the high amplitude body surface electrocardiogram signal in ventricular fibrillation, compared with unsynchronized shocks (78.7 +/- 4.7 J; P <.05). In this study a biphasic, rounded waveform of total duration 6 or 12 ms, was optimal for the correction of electrically-induced ventricular fibrillation. Synchronization to the peak or trough of the high amplitude electrocardiogram signal gave a further reduction in the energy to defibrillate.

Animals↗

PubMed2002

Response without shrinkage in bilateral Wilms tumor: significance of rhabdomyomatous histology.

PURPOSE: To test the hypothesis that poor response to chemotherapy in patients with bilateral Wilms tumor may be associated with the appearance of rhabdomyomatous histology, suggesting a differentiation response. METHODS: Twenty-six patients with bilateral Wilms tumor were treated at the authors' hospital between 1985 and 1995. Radiologic response to presurgical chemotherapy was assessed, and postsurgery histology was reviewed. RESULTS: There was a significant association between rhabdomyomatous differentiation in postchemotherapy surgical specimens and poor radiologic response. Poor response did not, however, necessarily mean poor outcome: of 11 patients with rhabdomyomatous differentiation, 7 are alive and disease-free, 2 died of complications, and only 2 died of uncontrolled Wilms tumor. CONCLUSIONS: Rhabdomyomatous differentiation in postchemotherapy bilateral Wilms tumor is associated with poor radiologic response. This observation may indicate a differentiation response rather than an absolute failure of response to chemotherapy. Clinical measures other than tumor volume are needed to distinguish between tumors that respond to chemotherapy but do not shrink, and those that genuinely do not respond.

Adolescent↗

PubMed2002

The loss rates for invasive prenatal testing in a specialised obstetric ultrasound practice.

OBJECTIVES: To establish the spontaneous miscarriage rate and compare it with the procedure related miscarriage rate for amniocentesis and chorionic villus sampling (CVS) by experienced operators. DESIGN: Retrospective audit over a two-year period of all patients having a consultation for prenatal diagnosis before 12 weeks gestation. SETTING: A specialised obstetric and gynaecological ultrasound practice. POPULATION: A total of 2366 patients, mostly over 35 years of age. METHODS: Between 1 July 1995 and 30 June 1997, all patients having a prenatal consultation decided between amniocentesis, CVS or no invasive testing. The CVS was performed either transabdominally or transcervically, depending on the position of the uterus and placenta. MAIN OUTCOME MEASURES: Delivery, termination of pregnancy for chromosomal abnormality or miscarriage. RESULTS: Over the two-year period, 2366 patients had a prenatal consultation and outcome data were available for all but 53 patients. After consultation, 346 patients decided not to have any prenatal testing and 29 (8.4%) of these had a spontaneous miscarriage. Amniocentesis was requested by 839 patients; however 10 miscarried before the scheduled procedure. After the amniocentesis, there were 13 terminations for chromosomal abnormality and three miscarriages. CVS was requested by 1128 patients; however, 23 miscarried before the scheduled procedure. Transabdominal CVS was performed in 665 patients, transcervical in 416 and in 24 cases the documentation of the method used was unclear. Eleven patients miscarried after the transabdominal CVS (1.65%) compared with nine patients miscarrying after the transcervical CVS (2.16%), which was not statistically significant (p = 0.27). CONCLUSION: In the group studied, the spontaneous miscarriage rate from nine weeks gestation is very high (8.4%). The procedure-related loss rate from amniocentesis was less than 1 in 280. Transabdominal CVS appears to have a lower fetal loss rate than transcervical CVS, but much larger numbers are needed to prove this.

Abortion, Spontaneous↗

PubMed2002

Prevalence, distribution, and host range of Peste des petits ruminants virus, Turkey.

Peste des petits ruminants virus (PPRV, genus Morbillivirus), which causes a severe disease in sheep and goats, has only recently been officially declared to be present in Turkey. We carried out a study to determine the prevalence, distribution, and host range of PPRV in Turkey. A total of 1,607 animals, reared in 18 different locations, were monitored for the presence of antibodies to PPRV and the related virus of large ruminants, Rinderpest virus (RPV). Only two farms had animals that were free of antibody responses to either disease. Prevalence for PPRV infection varied (range 0.87%-82.6%) and was higher in sheep (29.2%) than in goats (20%). The overall antibody responses to PPRV and RPV were 22.4% and 6.28%, respectively. Two PPRVs of lineage 4, which comprises many other PPRVs whose origins are in the Middle East, the Arabian Peninsula, and southern Asia, were isolated from Turkish sheep.

Animals↗