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Biomedical subjects

I Jacobs

Publications and source records attributed to I Jacobs.

At least 19 recordsLinked to original sources

Community attitudes towards performing cardiopulmonary resuscitation in Western Australia.

OBJECTIVE: to determine the attitudes of the Western Australian community towards performing cardiopulmonary resuscitation, and the factors affecting these attitudes. METHODS: telephone survey of a randomly selected sample of people from suburban Perth and rural Western Australia; practical assessment of a sub-sample of volunteers from those surveyed, to correlate survey answers with practical skills. RESULTS: of 803 people surveyed, the majority (90.7%) definitely would give mouth-to-mouth ventilation to a friend or relative, but less than half (47.2%) would to a stranger. The reluctance was mostly (56%) because of health and safety concerns, particularly related to HIV infection. Higher percentages of people would definitely provide cardiac massage for a friend or relative (91.4%) or stranger (78.1%). People were more likely to give mouth-to-mouth and cardiac massage if they had been trained in cardiopulmonary resuscitation (CPR), trained several times, trained recently, and used their CPR skills in real life. There were no significant differences between city and country people in whether they would provide CPR, but older people were less willing to provide mouth-to-mouth or cardiac massage. On practical assessment of 100 volunteers, there were significant errors and omissions in airway assessment, mouth-to-mouth resuscitation and cardiac massage. Volunteers with better practical scores were more prepared to provide CPR. DISCUSSION: our results indicate a significant reluctance of the Western Australia public to perform mouth-to-mouth, except to a friend or relative. Earlier CPR training, practice and use seemed to diminish this reluctance. Practical CPR skills were not well executed. Those with better skills were less reluctant to use them. We recommend increasing CPR training in the community, greater frequency of refresher courses and public education on the risks of CPR to improve rates of bystander CPR.

Attitude to Health↗

Randomized controlled trial of midazolam premedication to reduce the subjective adverse effects of adenosine.

OBJECTIVE: To determine the safety and efficacy of midazolam premedication to minimize the subjective adverse effects of adenosine. METHODS: Double-blind prospective randomized controlled trial of patients presenting to an urban emergency department. Included were a convenience sample of patients who would have received adenosine by the existing department protocol. Exclusion criteria were pregnancy, benzodiazepine allergy, regular benzodiazepine medication, alcoholism, altered mental state (precluding informed consent), and age less than 18 or greater than 65 years. Subjects received either 1.5 mg of intravenous midazolam or normal saline placebo 5 min prior to the administration of adenosine. Side-effect recall was judged by a questionnaire at 1 h and 24 h postadenosine administration. RESULTS: A total of 34 patients were recruited into the trial, 16 in the placebo group and 18 in the midazolam group. The groups were well matched for demographics, treatment and outcome. There was a significant reduction in the midazolam group for complaint scores of palpitations (P = 0.04) and chest pain (P = 0.02) and a trend to reduction in complaint scores for most other parameters. There were no adverse outcomes in any of the patients studied. CONCLUSIONS: Co-administration of midazolam can safely reduce the recall of the unpleasant adverse effects of adenosine. Its use may be most appropriate in patients who are particularly anxious or have had previous adverse experiences with adenosine.

Adenosine↗

Implementation and evaluation of an undergraduate emergency medicine curriculum.

OBJECTIVE: To describe the implementation and evaluation of an undergraduate course in the first Australian academic emergency medicine unit. METHODS: A descriptive study of a course involving fifth year medical students at the University of Western Australia was undertaken. Teaching included self-directed case problem solving, small group tutorials, practical-skills teaching, clinical attachments and information handouts. Evaluation involved questionnaire scores and written feedback regarding life-support skills, tutorial teaching, course materials, clinical attachments and the course in general. Some groups of students underwent pre-course and post-course examinations. RESULTS: Subjective and objective testing showed that student knowledge significantly improved. Feedback was especially positive toward clinical attachments in emergency departments, practical skills tutorials and the case-based learning method. Students requested longer attachments to emergency departments, and more practical, case-based, interactive and bedside teaching. Problems encountered included inadequate time for teaching, vagueness about student roles and objectives, and dealing with death for the first time without adequate preparation. CONCLUSION: Undergraduate emergency medicine education should become an essential part of Australian and international undergraduate medical education. Emergency medicine is enjoyable and eminently suitable for problem-based, interactive and integrated teaching and improves confidence, clinical experience in emergencies, practical skills and teamwork. Improvements include more problem-based teaching, more practical skills sessions and better definition of student roles. These are general principles that can be applied to other undergraduate courses and to designers of other emergency medicine courses, both undergraduate and postgraduate.

Analysis of Variance↗

Action sequence for layperson cardiopulmonary resuscitation.

Although some minor modifications were forged, the general consensus was to maintain most of the current guidelines for phone first/phone fast, no-assisted-ventilation CPR, the A-B-C (vs C-A-B) sequence of CPR, and the recovery position. The decisions to leave these guidelines as they are were based on a lack of evidence to justify the proposed changes, coupled with a reluctance to make revisions that would require major changes in worldwide educational practices without such evidence.Nonetheless, some major changes were made. The time-honored procedure ol pulse check by lay rescuers was eliminated altogether and replaced with an assessment for other signs of circulation. Likewise, it was recommended that even the professional rescuer now check for these other signs of circulation. Although professional rescuers may simultaneously check for a pulse, they should do so only for a short period of time (within 10 seconds). There was also enthusiasm for deleting the ventilation aspect of EMS dispatcher-assisted CPR instructions that are provided to rescuers at the scene who are inexperienced in CPR. lt was made clear, though, that the data are applicable only to adult patients who are receiving CPR and that the data are appropriate most for EMS systems with rapid response times.

Adult↗

The chain of survival.

Explore the source record for details and available documents.

Advanced Cardiac Life Support↗

Effect of caffeine and ephedrine ingestion on anaerobic exercise performance.

PURPOSE: Ingestion of a combination of caffeine (C) and ephedrine (E) prolongs time to exhaustion during high-intensity aerobic exercise. CNS stimulation by C and E was proposed as part of the mechanism for the improvement. It was thought that this arousal might also be of benefit during anaerobic exercise. The purpose of this study was to investigate the effect of C, E, and C+E ingestion on performance of anaerobic exercise. METHODS: Two groups were used to evaluate the effect of C and E on anaerobic performance. Group 1 (WIN) consisted of 16 healthy untrained male subjects who performed a 30-s Wingate test. Group 2 (MAOD) consisted of 8 healthy untrained male subjects who performed a supramaximal (125%VO(2peak)) cycle exercise trial to exhaustion to determine maximum accumulated oxygen deficit. The trials commenced 1.5 h after ingesting either C (5 mg x kg(-1)), E (1 mg x kg(-1)), a combination of C+E, or a placebo (P). All trials were randomized and double blind. Blood samples were assayed for lactate and glucose post drug ingestion just before exercise, and again 3, 5, and 10 min post exercise. Catecholamines were measured in the preexercise and 10-min postexercise blood samples. RESULTS: Ephedrine increased power output during the early phase of the Wingate test, whereas C increased time to exhaustion and O(2) deficit during the MAOD test. C, E, and C+E increased blood lactate, glucose, and catecholamine levels. CONCLUSION: The improvement in anaerobic exercise performance is likely a result of both stimulation of the CNS by E and skeletal muscle by C.

Adult↗

Changes in respiratory function during a wilderness multisport endurance competition.

OBJECTIVE: To document the changes in respiratory function seen in competitors during a typical wilderness multisport endurance event. METHODS: A prospective observational cohort study measuring forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) at baseline, midrace, and end of race in competitors in a 105-km ski/run/cycle/paddle race held midwinter in the mountains of Victoria, Australia. RESULTS: Twenty-five adult subjects (22 men) between 20 and 42 years of age were studied. The mean decline in FEV1 was 15.1% (95% CI 10.3-19.8) and for FVC was 13.0% (95% CI 8.1-17.9). Fourteen (56%) of the 25 subjects had a >10% decline in FEV1 and FVC, and 7 (28%) of the 25 subjects had a >20% decline. In 9 control subjects, aged between 21 and 55 years, there was no significant change in FEV1 or FVC from prerace to end of race. CONCLUSIONS: Significant declines in FEV1 and FVC are common during wilderness multisport endurance events. The focus of future research should be the etiology, which as yet remains speculative.

Adult↗

MR imaging of uterine sarcomas.

OBJECTIVE: The MR imaging appearances of uterine sarcomas are not well described in the literature. We describe the MR imaging features of uterine sarcomas. MATERIALS AND METHODS: MR images from all patients with histologically proven uterine sarcomas scanned between 1993 and 2000 were reviewed. Tumor size, its relationship to the uterus, signal characteristics, and enhancement pattern after IV injection of gadolinium were noted. RESULTS: Twenty-five scans from 22 patients were reviewed. Findings from the scans included 11 leiomyosarcomas, five mixed müllerian tumors, two rhabdosarcomas, and four endometrial stromal sarcomas. Two patterns of disease were observed, including a characteristic large heterogenous pelvic mass (n = 17) and an endometrial mass indistinguishable from endometrial carcinoma (n = 8). On T2-weighted images, the large masses were characteristically of low or intermediate background signal intensity with pockets of very high T2 signal. The areas of high T2 signal corresponded to cystic necrosis in the tumor. Pockets of high T1-weighted signal corresponded to hemorrhage. Gadolinium enhancement was present in the solid components of all tumors. This pattern was observed in all recurrent sarcomas. Some correlation was shown between the histologic subtypes and the MR imaging appearances. CONCLUSION: Uterine sarcomas show two patterns on MR imaging. The most common presentation is a large heterogenous mass. However, sarcomas can mimic endometrial carcinoma.

Adult↗

Characterization of nicotinic acetylcholine receptor-mediated [(3)H]-dopamine release from rat cortex and striatum.

The objective of this study was to use a new high throughput method to compare nicotinic acetylcholine receptor (nAChR)-mediated [(3)H]-dopamine (DA) release from slices of rat striatum and cortex. (-)Nicotine, (-)-cytisine, 1,1-dimethyl-4-phenyl-piperazinium (DMPP), and (+/-)-epibatidine evoked release of striatal [(3)H]-DA with pEC(50) values of 6.7, 8.25, 5.11, and 9.08, respectively. The same agonists evoked release of cortical [(3)H]-DA with pEC(50) values of 6.98, 8.06, 5.58, and 9.59. Relative to (-)-nicotine, (-)-cytisine was a partial agonist in both tissues. In contrast, the maximal response evoked by DMPP differed between the two tissues. The rank order of potency for antagonists to block DA release was the same (mecamylamine (Mec)>dihydro-beta-erythroidine (DHbetaE)>hexamethonium (Hex)>D-tubocurarine (D-TC)); however, the pIC(50) values varied between the two regions. Whereas Mec potently antagonized (-)-nicotine-evoked DA release similarly from striatum and cortex, with pIC(50) values of 6.07 and 6.53 respectively, the values obtained for DHbetaE, D-TC and Hex differed. Additionally, the present study was able to distinguish exocytotic vesicular-mediated from transporter-mediated DA release, by altering temperature of the incubation and exclusion of calcium. Assays carried out under these conditions indicate that approximately 60% of nicotine-evoked cortical DA release was likely mediated through the DA transporter. In contrast, under the same conditions only 15%-20% of striatal release appeared to be transporter-mediated. We conclude that the relative contributions of the mechanisms by which (-)-nicotine evokes DA release differ between striatum and cortex. In addition, the data suggest that the subtypes of nAChRs involved in regulating [(3)H]-DA release may be somewhat different in the two tissues.

Alkaloids↗

Assessment of nicotinic acetylcholine receptor-mediated release of [(3)H]-norepinephrine from rat brain slices using a new 96-well format assay.

The study of the modulatory effects of nicotinic acetylcholine receptor (nAChR) agonists on neurotransmitter release from tissue slices has been hampered by laborious and limiting superfusion techniques. A new methodology was developed utilizing 96-well filter plates. This new method produced comparable results to previously published data, yet expanded throughput to permit more complete pharmacological characterization. Rat brain slices, preloaded with [(3)H]-norepinephrine ([(3)H]-NE), were distributed onto 96-well filter plates. Following a 5 min preincubation, the slices were incubated for 5 min with nicotinic agonists or antagonists. (-)-Nicotine (NIC) and 1,1-dimethyl-4-phenylpiperazine (DMPP) evoked release of [(3)H]-NE from a number of brain regions and spinal cord, with the highest response seen in the hippocampus. Concentration-response curves revealed a rank order of potency of (+/-)-epibatidine>>anatoxin-a>A-85380>DMPP=NIC=(-)-cytisine in the hippocampus, thalamus, and frontal cortex. EC(50) values were approximately 0.005, 0.2, 1, 5, 5 and 5 microM, respectively. Concentration-inhibition curves of nicotine evoked [(3)H]-NE release from hippocampal and thalamic slices resulted in a rank order of potency of mecamylamine>hexamethonium>d-tubocurare>DHbetaE. Schild analysis revealed apparent noncompetitive antagonism of [(3)H]-NE release from hippocampus by mecamylamine, hexamethonium, and DHbetaE. In contrast, DHbetaE antagonism of [(3)H]-dopamine release from striatal slices using a similar methodology was competitive.

Animals↗

Preoperative diagnosis of the primary fallopian tube carcinoma by three-dimensional static and power Doppler sonography.

OBJECTIVE: To investigate whether three-dimensional static and power Doppler ultrasound improves the diagnosis of primary Fallopian tube carcinoma. METHODS: During a 2-year period five cases of primary Fallopian tube carcinoma were selected from a cohort of 520 patients with a previous scan suggestive of an adnexal tumor. RESULTS: Tubal malignancy occurred in patients between 49 and 64 years, with presenting symptoms such as pain, vaginal bleeding and leukorrhea. CA 125 was elevated in three cases of tubal carcinoma with stages II and III, while in two patients with stage I, CA 125 was within the normal limits. Two-dimensional ultrasound demonstrated sausage shaped cystic masses with papillary projections in two patients and a complex adnexal mass in one patient. Three-dimensional ultrasound revealed sausage shaped cystic and/or complex masses with papillary projections in all five cases of tubal malignancy. In one patient preoperative 3-D ultrasound correctly predicted bilateral tumors, while 2-D transvaginal sonography found only unilateral changes. Additional 3-D power Doppler examination depicted vascular geometry typical for malignant tumor vessels such as arteriovenous shunts, microaneurysms, tumoral lakes, blind ends and dichotomous branching in each of the cases with Fallopian tube carcinoma. CONCLUSIONS: Three-dimensional ultrasound allows precise depiction of tubal wall irregularities such as papillary protrusions and pseudosepta. Improved understanding of anatomical relationships may aid in distinguishing ovarian from tubal pathology. Multiple sections of the tubal sausage like structures enable determination of local tumor spread and capsule infiltration. Study of the vascular architecture in cases of Fallopian tube malignancy is further enhanced using 3-D power Doppler imaging.

Aged↗

Patterns in the incidence of age-related ovarian cancer in South East England 1967-1996.

OBJECTIVE: To study the age-related trends in the incidence rates of ovarian cancer in South East England between 1967 and 1996. DESIGN: A retrospective review of systematically collected data on ovarian cancer in South East England. METHODS: Data were obtained from the Thames Cancer Registry on the numbers and rates per 100,000 population of ovarian cancer per five-year age group (0-85+) in the 30-year period from 1967 to 1996 from the 26 health authorities in the Thames region. Linear regression was performed to determine the changes in incidence rates of ovarian cancer per age group over time. MAIN OUTCOME MEASURES: The change in overall incidence of ovarian cancer in South East England, as well as the change in incidence of ovarian cancer in each five-year age groups (20-85+) in the 30-year study period. RESULTS: There was a strong positive correlation between ovarian cancer rates and year of diagnosis in women aged > or = 70 years, and this was particularly marked in women > 85 years of age. There was a negative correlation between rates and year of diagnosis in women aged 45-59 years. The analysis did not demonstrate a significant correlation between ovarian cancer rates and year of diagnosis in women < 44 years of age or women aged 60-69 years. CONCLUSIONS: There have been significant changes in the pattern of ovarian cancer incidence in South East England during the 30-year period studied. The observed changes in ovarian cancer incidence in younger women may, in part, be explained by known reproductive factors. The rise in ovarian cancer rates among the older age group is difficult to explain, but has important implications for the future planning and provision of cancer services.

Adult↗

The accuracy of oral predictive and infrared emission detection tympanic thermometers in an emergency department setting.

OBJECTIVE: To assess the accuracy of an oral predictive thermometer and an infrared emission detection (IRED) tympanic thermometer in detecting fever in an adult emergency department (ED) population, using an oral glass mercury thermometer as the criterion standard. METHODS: This was a single-center, nonrandomized trial performed in the ED of a metropolitan tertiary referral hospital with a convenience sample of 500 subjects. The temperature of each subject was taken by an oral predictive thermometer, an IRED tympanic thermometer set to "oral" equivalent, and an oral glass mercury thermometer (used as the criterion standard). A fever was defined as a temperature of 37.8 degrees C or higher. The subject's age, sex, triage category, and diagnostic group were also recorded. Sensitivity, specificity, positive and negative likelihood ratios, positive and negative predictive values, and corresponding 95% confidence intervals were calculated. Logistic regression was used to identify predictors of fever. RESULTS: The sensitivities and specificities for detection of fever of the predictive and the IRED tympanic thermometers were similar (sensitivity 85.7%/88.1% and specificity 98.7%/95.8%, respectively). The predictive thermometer had a better positive predictive value (85.7%) compared with the IRED tympanic thermometer (66.1%). The positive and negative likelihood ratios for the predictive oral thermometer were 65 and 0.14, respectively, and for the IRED tympanic thermometer 21 and 0.12, respectively, indicating that the predictive thermometer will "miss" 1 in about 7 fevers and the IRED tympanic thermometer will "miss" 1 in about 8 fevers. CONCLUSIONS: Although quick and convenient, oral predictive and IRED tympanic thermometers give readings that cannot always be relied on in the detection of fever. If we are to continue using electronic thermometers in the ED setting, we need to recognize their limitations and maintain the importance of our clinical judgment.

Emergency Service, Hospital↗

Comparison of thermoregulatory responses between men and women immersed in cold water.

Eleven women (age = 24.4 +/- 6.3 yr, mass = 65.0 +/- 7.8 kg, height = 167 +/- 8 cm, body fatness = 22.4 +/- 5.9%, mean +/- SD) were immersed to neck level in 18 degrees C water for up to 90 min for comparison of their thermal responses with those of men (n = 14) in a previous similarly conducted protocol. Metabolic rate increased about three times resting levels in men and women, whereas the rate of rectal temperature cooling (DeltaT(re)/Deltat) in women (0.47 degrees C/h) was about one-half that in men. With use of all data, DeltaT(re)/Deltat correlates with the ratio of body surface area to size and the metabolic rate of shivering correlates inversely to the square root of body fatness. No significant gender differences in total metabolic heat production normalized for body mass or surface area were found among subjects who completed 90 min of immersion (9 women and 7 men). Nor was there a gender difference in the overall percent contribution ( approximately 60%) of fat oxidation to total heat production. Blood concentrations of free fatty acids, glycerol, beta-hydroxybutyrate, and lactate increased significantly during the 90-min immersion, whereas muscle glycogen sampled from the right quadriceps femoris vastus lateralis decreased (free fatty acids, glycerol, and beta-hydroxybutyrate were higher in women). When the subjects were subgrouped according to similar body fatness and 60 min of immersion (6 women and 5 men), no significant gender differences emerged in DeltaT(re)/Deltat, energy metabolism, and percent fat oxidation. These findings suggest that no gender adjustments are necessary for prediction models of cold response if body fatness and the ratio of body surface area to size are taken into account and that a potential gender advantage with regard to carbohydrate sparing during cold water immersion is not supported.

Adipose Tissue↗