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Biomedical subjects

M Burns

Publications and source records attributed to M Burns.

At least 37 records · Page 2Linked to original sources
PubMed1996

Sign tracking versus goal tracking in the sexual conditioning of male Japanese quail (Coturnix japonica).

Pairings of a conditioned (CS) and unconditioned (US) stimulus can result in approach to either the CS (sign tracking) or the US (goal tracking). Increasing the spatial or temporal separation between the CS and a US food has been reported to results in a decline in sign tracking and an increase in goal tracking. In the present experiments, sign tracking was the predominant response of male quail (Coturnix japonica) to a CS that was presented up to 91 cm from the door through which a female was presented as the US (Experiment 1). Contrary to reported results with food reinforcement, goal tracking was not facilitated by increasing the spatial separation between the CS and US (Experiment 2) or by introducing a trace interval between them (Experiment 3). The preponderance of sign tracking may reflect an adaptive specialization of sexual conditioning or may be related to the absence of magazine training and the use of a moving US in the sexual conditioning procedures.

Animals↗
PubMed1996

Outcomes research: contemporary issues and historical significance for nurse practitioners.

Outcomes research is not new to the discipline of nursing. However, the driving forces of today's health care environment are resulting in increased emphasis on the study of outcomes. This article presents an overview of the scope of outcomes research, including a historical perspective and contemporary issues. Outcomes research provides an opportunity to demonstrate the effectiveness of nurse practitioner practice.

Humans↗
PubMed1995

Medical and health care needs of families providing in-home care for relatives with developmental disabilities.

The purpose of this investigation was to attempt to describe the health care needs of families providing in-home care to members with developmental disabilities as well as the characteristics and demographics of families providing in-home care. The survey included 761 families who participated in a federal demonstration project in rural southern Georgia. The results indicated that impoverished families need increased assistance to provide adequate medical and health care when providing in-home care to relatives experiencing developmental disabilities. Implications for administration of programs and development of policies are discussed.

Caregivers↗
PubMed1994

A laboratory study of patients with chronic allergic rhinitis: antihistamine effects on skilled performance.

Twenty-four patients with chronic allergic rhinitis participated in a study of antihistamine effects on skilled performance. They were tested while experiencing symptoms and when they were free of symptoms. Within each symptom condition, they attended two sessions; each patient received a placebo capsule at one session and a 50 mg diphenhydramine capsule at the other. Subjects performed a battery of skilled performance tests, which included the Divided-Attention, Visual Backward Masking, Stimulus Response Conflict, and Vigilance tests. They rated the treatments and their performance. Affective states were assessed with the Profile of Mood States. Symptoms did not affect performance. Diphenhydramine impaired vigilance performance and measures of Divided Attention and Stimulus Response Conflict. Visual Backward Masking performance was not affected. The largest performance changes occurred when diphenhydramine was administered to subjects when they were free of symptoms.

Adult↗
PubMed1993

Glomerular C3c localization indicates ongoing immune deposit formation and complement activation in experimental glomerulonephritis.

In antibody-mediated glomerular disease, deposits of C3 (C3b) are common and are degraded by factor I to C3c and C3d. However, the kinetics of C3b degradation in glomerulonephritis have not been defined. To do this, we studied three models of complement-dependent glomerulonephritis with established C3 deposits (passive Heymann nephritis, cationized immunoglobulin G membranous nephropathy, and concanavalin A-anticoncanavalin A glomerulonephritis). C3b deposition was halted by administration of cobra venom factor, and the disappearance of C3c and C3d from glomeruli was measured with specific antibodies and quantitative fluorescence densitometry. Results showed that C3c deposits were reduced by over 85% within 24 hours in all three models. C3c clearance was unaffected by site or mechanism of deposit formation. C3d deposits persisted despite lack of ongoing complement activation. In passive Heymann nephritis when disease activity was monitored by urinary C5b-9 excretion, C3c was cleared in parallel with return of urine C5b-9 excretion to normal values. We conclude that glomerular deposits of C3c are cleared within 24 hours of cessation of complement activation. Positive staining for C3 utilizing antibody specific for the C3c portion documents recent complement activation usually reflecting new immune deposit formation.

Animals↗
PubMed1990

Plasma GABA-like activity in response to ethanol challenge in men at high risk for alcoholism.

Sons of alcoholic fathers (high risk, HR) and matched control men from families without alcoholism (low risk, LR) were administered, in a randomized double-blind fashion, either a placebo beverage or an isovolemic beverage containing ethanol (0.8 g/kg). Serial blood sampling for determination of plasma gamma-aminobutyric acid (GABA)-like activity, mood, and intoxication ratings were performed. The HR subjects were found to have significantly less plasma GABA-like activity than LR during the placebo condition. The alcoholic beverage condition washed out the differences in plasma GABA between groups. Significant interactions between risk group status and beverage conditions were found with respect to plasma GABA-like activity. Alcohol produced an increase in mean GABA-like activities among HR subjects, whereas a slight decline was noted among LR subjects. Plasma GABA-like activity also had a significant inverse correlation with self-reports of perceived tension in the placebo condition, and tension, confusion, and intoxication in response to the alcoholic drink. Since previous investigators have reported reduced plasma GABA levels in alcoholic individuals, reduced plasma GABA-like activity may be a biological marker for vulnerability to alcoholism or for heightened tension as a behavioral factor that predisposes to alcoholism.

Adult↗
PubMed1990

Comprehensive management of renal failure in infants.

From 1986 through 1989, 23 infants (18 of whom were less than 30 days old) required peritoneal dialysis within their first 6 months of life. Modifications to conventional peritoneal dialysis included modified Silastic Tenckhoff catheters, peel-away sheaths for percutaneous insertion, automated peritoneal dialysis "cyclers," and generous omentectomy. With these modifications, there were no bowel perforations, and the infants were successfully dialyzed for prolonged periods. Eight of the 23 infants developed end-stage renal failure and were prepared for transplantation. All had gastrostomy tubes placed to supplement oral nutrition. Living, related transplantation was performed when the child weighted 10 kg. Four of the eight completed this protocol. One child with congenital nephrotic syndrome died before transplantation. One transplant was complicated by a technical problem (venous thrombosis), which resulted in allograft loss and return to peritoneal dialysis. Kidney function, growth, and development in the survivors were excellent.

Catheters, Indwelling↗
PubMed1990

Phospholipid hydrolysis and loss of membrane integrity following treatment of rat brain synaptosomes with beta-bungarotoxin, notexin, and Naja naja atra and Naja nigricollis phospholipase A2.

The effects of the phospholipase A2 (PLA2) toxins, beta-bungarotoxin and notexin, and the PLA2 enzymes from Naja naja atra and Naja nigricollis snake venoms on the plasma membrane integrity of synaptosomes were examined. Synaptosomes were isolated from rat brain cerebral cortex, corpus striatum and hippocampus. Osmotic activity, lactate dehydrogenase leakage, and leakage of 2-deoxy-D-(1-3H)-glucose-6-phosphate were monitored (37 degrees C, 10-120 min) following incubation with 0.5, 5 and 50 nM concentrations of toxins and enzymes. Damage to the synaptosomal plasma membrane was time and concentration but not tissue dependent. The potencies of the treatments were as follows: N. n. atra PLA2 greater than or equal to N. nigricollis PLA2 greater than notexin greater than beta-bungarotoxin. Chelation of Ca2+ with 5 mM EDTA completely inhibited plasma membrane disruption caused by beta-bungarotoxin and N. n. atra PLA2. One mg/ml of bovine serum albumin also blocked the disruptive action of N. n. atra PLA2, while 8 mg/ml was required to antagonize beta-bungarotoxin. A correlation between phospholipid hydrolysis and loss of membrane integrity was also observed. The generation of phospholipid hydrolytic products may be critical in the permeabilization of synaptic plasma membranes by these toxins and enzymes, however, they do not explain the presynaptic specificity and potency of beta-bungarotoxin and notexin.

Animals↗
PubMed1990

Laboratory study of drug-related performance changes.

Performance decrements associated with therapeutic drugs may increase the risk of many common activities that require intact skills. However, accident data that define such risks are difficult to obtain, and the assessment of skill decrements often must be based on data obtained from the laboratory study of drug effects. The validity and reliability of conclusions drawn from laboratory data are a function of experiment design and measurement methods. Critical issues include the assumptions, rationale, and hypotheses underlying laboratory measurement of skills performance. Drug doses and dosing regimens, subject characteristics, and response measures are key variables that limit data interpretation. The design of reported experiments, including the selection of a battery of laboratory tests, reveals the underlying issues, and data from the experiments demonstrate both valid conclusions and constraints on interpretation.

Cardiovascular System↗
PubMed1989

Outpatient pulmonary rehabilitation. A new lease on life.

For patients with restrictive as well as obstructive disease, pulmonary rehabilitation offers a comprehensive program that affects all areas of their life. Marked improvement is seen in exercise tolerance and in performing all activities of daily living. Compliance with drug therapy and other prescribed treatment also improves. The isolation, depression, and irritability that so often accompany respiratory disease are alleviated by ongoing membership in patient support groups. Patients again become active participants in life.

Ambulatory Care↗
PubMed1989

A new pendant oxygen-conserving cannula which allows pursed lips breathing.

Multiple benefits of oxygen therapy for hypoxemic patients with chronic lung disease are well established. Steady flow oxygen therapy is inefficient, wasteful and has a high cost. The Oxymizer pendant improves efficiency of oxygen delivery compared with SF. However, the device requires that the patient inhale and exhale nasally to maximize its oxygen-saving properties. When patients do PLB they may not receive full oxygen-saving benefit of the pendant. Yet PLB itself can increase SaO2. We evaluated an AP, which does not require nasal exhalation, in nine patients with COPD. We measured SaO2 while breathing oxygen via SF and the AP with nasal-only breathing and PLB. Results indicate that the AP maintains an increase in SaO2 over SF during nasal-only breathing and a further increase during PLB. We conclude that AP acts as an oxygen conserver during PLB; PLB with the AP achieves greater savings than with nasal-only breathing.

Aged↗
PubMed1989

Guideline report. Medical ultrasound imaging: progress and opportunities.

Utilization of medical ultrasound has expanded rapidly during the past several years. In 1988, sales of ultrasound equipment will approach $600 million, which is higher than any other individual imaging modality, including the most capital intensive, such as magnetic resonance imaging (MRI), computed tomography (CT), and cath lab angiography. This growth would have been difficult to predict previously, since ultrasound appeared to be a relatively mature imaging modality not too long ago. There are several reasons for this growth. Technological developments have been quite rapid; ultrasound has become easier to use, image quality has improved dramatically, and diagnostic accuracy has been enhanced. There has been a proliferation of new equipment at all ends of the price spectrum, allowing the user a wide choice in instrument performance, multi-function capabilities, and automated features to increase patient throughput. The DRG environment and the prospect for more pre-admission tests have also been a stimulus. Hospital buying activity has expanded, and many more ultrasound exams are now being conducted on an outpatient basis. Sales to freestanding imaging centers and individual physicians have similarly increased. The hospital user is willing to pay a large premium for advanced technical performance and is prepared to retire or replace older technology in less than three years. This replacement cycle is much shorter than the four to five year period which existed prior to 1985. By comparison, some of the more traditional imaging areas, such as radiology, have replacement rates of eight to ten years. The reason for early replacement is obvious. Ultrasound exams in hospitals generate revenues at a rate that justifies the purchase of the most advanced equipment. It also improves the referral rate and positions the hospital as a high quality provider. Even with low utilization rates, an ultrasound instrument can normally pay for itself in less than one year of regular use. Ultrasound is one of the safest and least invasive of any of the imaging modalities. It provides a high diagnostic yield relative to its cost. It is comfortable for the patient and can be performed in almost any setting. The equipment is mobile and is relatively easy to use for most examinations. All of these factors have encouraged its increased use. This report examines trends in the ultrasound field from both a technological and economic standpoint and should help end-users in understanding the potentials of this important imaging modality.

Costs and Cost Analysis↗
PubMed1988

Effects of terfenadine, diphenhydramine, and placebo on skills performance.

The behavioral effects of the antihistamines terfenadine and diphenhydramine were compared in a placebo-controlled, double-blind crossover study. Performance of skills deemed important in safe man-machine interactions was objectively assessed one, three, and five hours after administration of test substances. The results indicate that diphenhydramine use resulted in various degrees of impairment of the ability to perform a visual-search task, a tracking task, a divided-attention task, and a vigilance task. Terfenadine users performed as well as or better than placebo-treated subjects. No differences between terfenadine and placebo were found on a subjective evaluation scale. Diphenhydramine users consistently reported feelings of impairment.

Adult↗