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Biomedical subjects

D L Robinson

Publications and source records attributed to D L Robinson.

At least 37 records · Page 2Linked to original sources
PubMed1999

The technical, neurological and psychological significance of 'alpha', 'delta' and 'theta' waves confounded in EEG evoked potentials: a study of peak latencies.

It is suggested that lack of progress in understanding the neurological and psychological significance of EEG averaged evoked potentials (AEPs) and event related potentials (ERPs) may be due to the confounding of, 'delta', 'theta' and 'alpha' frequency responses generated by the 'brain-stem' 'limbic' and 'thalamic' cortical activating systems, respectively. This hypothesis was tested in a sample of 93 adults by recording EEG responses to auditory tones and using narrow-band filters to distinguish '4 Hz', '7 Hz', and '10 Hz' component waves in the unfiltered AEP. Bivariate and multivariate statistical analyses of peak latencies provided evidence of the distinct and unitary nature of these component waves and demonstrated their relative influence on the P1, N1 and P2 peaks of the unfiltered AEP. The results also reveal a predicted negative relationship between the 10 and 4 Hz latencies which is attributed to inhibition of the delta frequency brain-stem ascending reticular activating system (BSARAS) by the alpha frequency diffuse thalamic projection system (DTPS). Correlations of the 4 Hz latencies, with age, sex, and behavioural arousal variables confirm that the 4 Hz latencies are associated with the maintenance of behavioural arousal, an important function of the BSARAS.

Adult↗
PubMed1999

An integrated physical map for the short arm of human chromosome 5.

The short arm of human chromosome 5 contains approximately 48 Mb of DNA and comprises 1.5% of the genome. We have constructed a mega-YAC/ STS map of this region that includes 436 YACs anchored by 216 STSs. By combining and integrating our map with the 5p maps of other groups using the same recombinant DNA library, a comprehensive map was constructed that includes 552 YACs and 504 markers. The YAC map covers >94% of 5p in four YAC contigs, bridges the centromere, and includes an additional 5 Mb of 5q DNA. The average marker density is 95 kb. This integrated 5p map will serve as a resource for the continuing localization of genes on the short arm of human chromosome 5 and as a framework for both generating and aligning the DNA sequence of this region.

Animals↗
PubMed1998

Addition of droperidol to morphine administered by the patient-controlled analgesia method: what is the optimal dose?

Eighty patients were recruited into a double-blind, randomized trial to find the optimal dose of droperidol for addition to the patient-controlled analgesia (PCA) morphine infusate for female patients undergoing gynaecological surgery. A standardized anaesthetic technique was employed. Post-operative analgesia was provided by PCA morphine. Patients were allocated at random into one of four treatment groups receiving with each PCA morphine bolus: (1) droperidol 0.05 mg; (2) droperidol 0.10 mg; (3) droperidol 0.15 mg; and (4) droperidol 0.20 mg, respectively. The incidence of post-operative nausea and vomiting (PONV), requests for rescue anti-emetic medication, and incidence of side effects were recorded. The number of symptom-free patients in each group increased as the droperidol dose increased, but although there was a significant inverse association between the total dose of droperidol received and the severity of PONV (P < 0.05), there were no significant differences between individual groups. In each group, patients were significantly less sedated at 24 h compared with 12 h (P < 0.01). However, after 24 h, patients in group 4 were significantly more sedated than patients in groups 1 and 2 (P < 0.05). There were no significant differences between the groups in terms of the incidence of anxiety or other side effects attributable to droperidol. The present authors suggest that, although the results demonstrate few statistically significant differences between the four groups, a PCA bolus dose of droperidol of 0.10 mg mL-1 appears to provide the optimal balance between anti-emetic efficacy and an acceptable incidence of side effects.

Adolescent↗
PubMed1997

Bacterial endocarditis in hemodialysis patients.

Infective endocarditis (IE) is one of the most serious complications of bacteremia. Hemodialysis patients with prosthetic vascular access devices such as dual-lumen cuffed venous catheters and polytetrafluoroethylene (PTFE) grafts are at increased risk for bacteremia compared with patients with primary arteriovenous fistulae (PAVF). We present 20 cases of IE in hemodialysis patients seen at our institution over a 7-year period. Eight patients had PTFE grafts, 11 had dual-lumen cuffed catheters, and one had a PAVF. All patients underwent transthoracic echocardiography (TTE) and 16 patients also received transesophageal echocardiography (TEE). The Duke Criteria were used to characterize patients as definite or possible IE. Organisms were Staphylococcus aureus (55%), Staphylococcus epidermidis (25%), and Enterococcus sp (10%). The mitral valve (50%) was the most commonly affected valve, followed by aortic (30%) and right-sided IE (25%). Valve replacement was performed in five patients, of whom three survived hospitalization. The overall mortality rate for the series was 30%. All the dual-lumen cuffed catheters were removed, while only two of the eight PTFE grafts were removed. Four of the six patients who died had PTFE grafts, of which one was judged to be infected and removed. Echocardiography was essential to the diagnosis of IE. Vegetations were found in 50% by TTE and 81% by TEE. Six patients with no vegetations on TTE were found to have vegetations on TEE.

Arteriovenous Shunt, Surgical↗
PubMed1997

Family stress theory: implications for family health.

The Resiliency Model of Family Stress, Adjustment and Adaptation explains variations in how families respond to stressful situations and crisis. Key concepts of the model and supporting research are presented. Suggestions for ways to use the Resiliency Model in practice are provided. This article demonstrates the value of theory-based nurse practitioner practice by describing how assessment and interventions based on the Resiliency Model can assist the family nurse practitioner in supporting and guiding a family in crisis.

Adaptation, Psychological↗
PubMed1997

Telephone advice: new solutions for old problems.

This article describes the increasing use of the telephone as a means for seeking medical care. The literature is reviewed concerning the problems and pitfalls of telephone advice. The legal/ethical implications of health care providers giving telephone advice are discussed. Recommendations for the assessment of need, planning, implementation, and organization of a consistent telephone advice program are stressed. The development of a quality assurance program to maintain the quality of the advice program is presented. Suggestions for training of personnel and the importance of documentation of calls are included.

Clinical Protocols↗
PubMed1996

Shared neural control of attentional shifts and eye movements.

We are able to move visual attention away from the direction of gaze, fixating on one object while attending to something else at a different location, within the region of peripheral vision. It has been widely assumed that the attentional neural systems are separate from the motor systems, but some studies challenge this idea. It has now been suggested that the attentional system is part of the premotor processing in the brain. This model proposes that attentional processes evolved as part of the motor systems, with isolated attentional shifts representing an artificial separation of a natural linkage. Here we test how attentional shifts might be linked to the preparations for making saccadic eye movements. We studied the superior colliculus in monkeys as they shifted their attention during different tasks, and found that each attentional shift is associated with eye-movement preparation.

Animals↗
PubMed1996

The generation and regional localization of 303 new chromosome 5 sequence-tagged sites.

With the ultimate goal of creating a sequence-ready physical map of all of chromosome 5, 303 new human chromosome 5-specific STS markers have been systematically generated and regionally ordered. Chromosome 5 DNA prepared from flow-sorted chromosomes was digested with restriction enzymes BamHI and HindIII and cloned in bacteriophage M13mp18. Random clones were sequenced, and appropriate PCR deoxyoligomers were synthesized. An acceptable sequence-tagged site (STS)-PCR assay yielded the appropriate size amplification product from both total human DNA and hybrid cell line DNA containing only human chromosome 5. Each STS has been regionally localized by breakpoint analysis using a set of hybrid cell panels consisting of natural deletions or translocations of human chromosome 5. This hybrid cell panel was able to localize the STSs to 1 of 51 bins on the short arm and 1 of 15 bins on the long arm. The STS markers appear to be randomly distributed along the length of this 194-Mb chromosome. The current overall density of these markers (approximately 1 STS/640 kb), combined with the numerous PCR-based physical and genetic markers generated by other groups, will provide sufficient "nucleation points" for YAC contig assembly and verification in any region of human chromosome 5.

Animals↗
PubMed1996

Head injuries and bicycle helmet laws.

The first year of the mandatory bicycle helmet laws in Australia saw increased helmet wearing from 31% to 75% of cyclists in Victoria and from 31% of children and 26% of adults in New South Wales (NSW) to 76% and 85%. However, the two major surveys using matched before and after samples in Melbourne (Finch et al. 1993; Report No. 45, Monash Univ. Accident Research Centre) and throughout NSW (Smith and Milthorpe 1993; Roads and Traffic Authority) observed reductions in numbers of child cyclists 15 and 2.2 times greater than the increase in numbers of children wearing helmets. This suggests the greatest effect of the helmet law was not to encourage cyclists to wear helmets, but to discourage cycling. In contrast, despite increases to at least 75% helmet wearing, the proportion of head injuries in cyclists admitted or treated at hospital declined by an average of only 13%. The percentage of cyclists with head injuries after collisions with motor vehicles in Victoria declined by more, but the proportion of head injured pedestrians also declined; the two followed a very similar trend. These trends may have been caused by major road safety initiatives introduced at the same time as the helmet law and directed at both speeding and drink-driving. The initiatives seem to have been remarkably effective in reducing road trauma for all road users, perhaps affecting the proportions of victims suffering head injuries as well as total injuries. The benefits of cycling, even without a helmet, have been estimated to outweigh the hazards by a factor of 20 to 1 (Hillman 1993. Cycle helmets-the case for and against. Policy Studies Institute, London). Consequently, a helmet law, whose most notable effect was to reduce cycling, may have generated a net loss of health benefits to the nation. Despite the risk of dying from head injury per hour being similar for unhelmeted cyclists and motor vehicle occupants, cyclists alone have been required to wear head protection. Helmets for motor vehicle occupants are now being marketed and a mandatory helmet law for these road users has the potential to save 17 times as many people from death by head injury as a helmet law for cyclists without the adverse effects of discouraging a healthy and pollution free mode of transport.

Accidents, Traffic↗
PubMed1996

Efficiency of a circle system for short surgical cases: comparison of desflurane with isoflurane.

Patients undergoing short surgical procedures but requiring ventilation of the lungs were allocated randomly to receive either desflurane or isoflurane by circle absorption system, initially at a high fresh gas flow. The inspired and expired concentrations of the volatile agent were measured and the fresh gas flows reduced to low flow (500 ml min-1 total when FE/FI = 0.8), as measured on a multigas analyser. In patients receiving desflurane (n = 32), the median time at which flows were reduced was 5 min (interquartile range (IQR) 1 min) while with isoflurane (n = 32), the median time was 19 (IQR 12) min. After the reduction in flow, expired concentrations of volatile agent decreased in both groups. In the isoflurane group the concentration continued to decrease during anaesthesia. In the desflurane group the initial decrease was followed by a slow recovery. We conclude that the circle system can be used efficiently for short anaesthetics using desflurane.

Adult↗
PubMed1996

Second licensure for advanced practice: current status.

This article provides a through update of second licensure for advanced practice nurses. The National Council of State Boards of Nursing (NCSBN) has proposed new requirements for legislation and licensure for advanced practice nurses. This proposal could have major repercussions for all advanced practice nurses, depending on whether the state boards of nursing adopt the council's recommendation. A review of the historical aspect and the development of nursing licensure is reported. Both the 1992 and 1995 second licensure proposals are analyzed. Support for and dissent against the proposals by nursing organizations and individuals in the nursing community are included. The current status of the proposal for second licensure by the National Council of State Boards of Nursing is high-lighted.

Humans↗