Biomedical subjects
S Butler
Publications and source records attributed to S Butler.
High frequency chest compression therapy: a case study.
A new device, the ThAIRapy Bronchial Drainage System, enables patients with cystic fibrosis to self-administer the technique of high frequency chest compression (HFCC) to assist with mucociliary clearance. We review the literature on HFCC and outline a case study of a patient currently using the ThAIRapy Bronchial Drainage System. While mucociliary clearance and lung function may be enhanced by HFCC therapy, more research is needed to determine its efficacy, cost benefits, and optimum treatment guidelines. Although our initial experience with the patient using this device has been positive, we were unable to accurately evaluate the ThAIRapy Bronchial Drainage System.
Case reports and hypothesis: a neglect-like syndrome may be responsible for the motor disturbance in reflex sympathetic dystrophy (Complex Regional Pain Syndrome-1).
Reflex sympathetic dystrophy (RSD, Complex Regional Pain Syndrome-1, CRPS-1) is a chronic pain disorder associated with autonomic dysregulation that most commonly involves a limb. In addition to pain, motor dysfunction in the involved extremity may be a significant cause of disability. To spur reassessment of underlying mechanisms and development of novel rehabilitative approaches for RSD, we propose a new hypothesis: a neurologic neglect-like syndrome may explain the motor dysfunction that occurs in a subgroup of RSD patients. This hypothesis is based on a selected series of 11 patients who underwent specific neglect testing. The etiology of neglect in RSD is not clear, but we hypothesize that changes within central nervous system (CNS) structures may occur following persistent abnormal activation of the peripheral and autonomic nervous systems, which then may result in a neglect-like syndrome. Further study is needed to verify our clinical observations and test this hypothesis.
Child maltreatment: the collaboration of child welfare, mental health, and judicial system.
The alliance of child welfare, mental health, and legal systems has received little empirical attention, despite the magnitude of its impact on children and families. We examined the congruence of child protection agencies legal positions, court clinic recommendations, and judicial dispositions in a sample of 59 contested child maltreatment cases. Placement recommendations/decisions among all three systems were highly correlated, although the relationship was not so strong as to undermine the independence of any one system. Where there was disagreement between successive evaluations, it was in the direction of enhancing family integrity and parental access rights. We advanced three hypotheses to account for our findings: (a) changes in successive recommendations reflect the increasing sophistication of the assessment process; (b) changes reflect increasing distance from the family's ecology and are therefore increasingly ill informed; and (c) the changes are purely probabilistic, reflecting a drift toward the societal status quo.
Successful pharmacologic treatment of massive atenolol overdose: sequential hemodynamics and plasma atenolol concentrations.
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Kinetics of crystallization in a shearing colloidal suspension.
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Physiological identification of the auditory nerve during surgery for acoustic neuroma.
We report the design and clinical use of an electrode which can locate the acoustic nerve fibres in the normal eighth nerve and also in eighth nerves deformed by acoustic neuromas. The improvement in facial nerve preservation during acoustic neuroma surgery is partly due to the use of a facial nerve stimulator to anatomically locate the fibres. Our new acoustic nerve detector has the capability of anatomical location of cochlear fibres which may help to improve hearing preservation in selected cases of acoustic neuroma. The device functions by detecting the compound action potential evoked by no frequency auditory simulation at 500 Hz. The 500 Hz compound action potential is detected with a bipolar probe and then amplified and filtered. This results in a 500 Hz tone when the probe contacts the auditory nerve. Detection is virtually instantaneous. The acoustic nerve detector (AND) is demonstrated in a normal eighth nerve complex and its use is then described in the total removal of an acoustic neuroma with a 1 cm extracanalicular extension in which useful hearing was saved post-operatively. The present prototype may not be sensitive enough to detect the very low signals that may result when cochlear fibres are widely distorted around a large tumour or in cases where slight contusion of the nerve occurs during dissection. In all other cases the real time anatomical information is extremely helpful in guiding acoustic nerve dissection and also in monitoring the effects of petrous bone drilling.
Efficient translation of poly(A)-deficient mRNAs in Saccharomyces cerevisiae.
The polyadenylate tail of eukaryotic mRNAs is thought to influence various metabolic phenomena including mRNA stability, translation initiation, and nucleo-cytoplasmic transport. We have analyzed the fate of mRNAs following inactivation of poly(A) polymerase in Saccharomyces cerevisiae containing a temperature-sensitive, lethal mutation (pap1-1) in the gene for poly(A) polymerase (PAP1). Inactivation of poly(A) polymerase (Pap1) by shifting cells to the nonpermissive temperature resulted in the loss of at least 80% of measurable poly(A) within 60 min. Northern blot analysis revealed the disappearance of some mRNAs (CYH2 and HIS4) consistent with a role for poly(A) tails in mRNA stability. However, other mRNAs (TCM1, PAB1, ACT1, and HTB2) accumulate as poly(A)-deficient (A < approximately 25) transcripts as defined by an inability to bind oligo(dT)-cellulose. Sucrose density gradient analysis of polyribosomes revealed a twofold reduction in the amount of each size class of polyribosomes in shifted cells and a commensurate increase in free ribosomes. However, poly(A)-deficient mRNAs in shifted cells remain associated with the same size polyribosomes as poly(A)+ mRNAs in unshifted cells, indicating normal initiation of translation. RNase mapping of transcripts from pap1-1 cells revealed PAB1 mRNA to be poly(A)- whereas TCM1 exists as equal amounts of poly(A)- and poly(A)+ mRNA 60 min after shift. Interestingly, both of these classes of TCM1 mRNA appear in similar amounts in each polyribosome fraction indicating that ribosomes may not distinguish between them. These findings suggest that under conditions of excess translational capacity, poly(A)- and poly(A)+ mRNAs may initiate translation with comparable efficiencies.
Evidence for altered alpha 2-adrenoceptor function following isolation-rearing in the rat.
This study investigated central alpha 2-adrenoceptor function in differentially reared rats. Rats reared from weaning were either housed singly or in groups of five. Measurements of spontaneous ambulatory activity at 4 weeks postweaning showed that isolates were more hyperactive on exposure to a novel environment than grouped rats. alpha 2-Adrenoceptors were investigated using alpha 2-adrenoceptor agonist-induced behaviours, [3H]-idazoxan binding and measurement of forskolin-stimulated cyclic AMP accumulation. Clonidine (0.001-1.0 mg/kg IP) induced mydriasis in both groups with no difference observed in the response between the isolation and group-reared animals. Clonidine (0.01-0.5 mg/kg IP) induced hypoactivity in both groups, with the effect significantly greater in the isolation-reared rats. Idazoxan markedly attenuated both responses, confirming their induction by alpha 2-adrenoceptor stimulation. Clonidine-induced hypoactivity and mydriasis are mediated by pre- and postsynaptic alpha 2-adrenoceptors, respectively; therefore the results suggest rats reared in isolation have enhanced presynaptic but unchanged postsynaptic alpha 2-adrenoceptor function. Saturation binding experiments using [3H]-idazoxan were undertaken to determine alpha 2-adrenoceptor number (Bmax) and affinity (Kd) in membranes prepared from the frontal cortex and hippocampus. Analysis of binding data revealed an increase in receptor number in the hippocampus of isolates. Cyclic AMP accumulation was measured in hippocampal slices from differentially reared rats. Isolation-rearing did not affect cyclic AMP accumulation in response to stimulation by forskolin (30 microM). However, the selective alpha 2-adrenoceptor agonist, UK14304, produced a significantly greater inhibition of cyclic AMP accumulation in slices from isolated rats, confirming changes in alpha 2-adrenoceptor function following isolation rearing.
Economics of health care reform.
Several economic points require consideration when assessing the current cost of health care in the United States and the potential savings from proposed reforms. Most savings projections are based on assumptions and estimates that cannot be accurate under the best of circumstances, and the error in the final results is greatly compounded by even small errors in the initial estimates. Experience with health care programs worldwide, including our own Medicare program, has shown that final costs are usually much larger--often several times larger--than initial estimates. It is even more difficult to predict the behavior of the population under a system that does not yet exist, and it is not clear whether a system such as the Jackson Hole Plan will actually produce savings. The effect of our political system will have on any health system enacted through legislation must also be considered. The political process itself frequently results in more benefits rather than fewer, more regulation rather than less, and the shifting of costs to other sectors of the economy to minimize costs in the health sector. When presented with projections and predictions in health care planning, we must critically examine the initial assumptions, knowing that errors in these assumptions will magnify errors in the final results.
A profile of mood in ambulatory nursing home residents.
This study examined mood in 54 ambulatory nursing home residents. Female subjects reported significantly lower scores on the Anger-Hostility subscale than either men or normative subjects. Women also scored lower than normative subjects on the Vigor-Activity and Confusion-Bewilderment subscales, whereas men scored lower on the Fatigue-Inertia subscale. Both men and women reported below norm scores for the Tension-Anxiety subscale. Further study is needed to identify sociological factors that may explain diminished expression of mood in this vulnerable population, and to compare these findings with the mood profile of community dwelling elders.
Cytokine elevations in critically ill infants with sepsis and necrotizing enterocolitis.
We hypothesized that plasma levels of cytokines such as interleukin-6 and tumor necrosis factor (TNF) are elevated in critically ill infants with sepsis and necrotizing enterocolitis (NEC) and that the magnitude of their elevation is correlated with mortality rate. We measured plasma levels of interleukin-6 and TNF in 62 newborn infants with suspected sepsis or NEC. Eighteen infants had bacterial sepsis, 9 had bacterial sepsis plus NEC, and 15 had NEC but negative culture results. Twenty comparably ill infants with negative results on culture of systemic specimens served as study control subjects. Interleukin-6 levels were five- to tenfold higher in infants with bacterial sepsis plus NEC at the onset of disease than in infants with bacterial sepsis alone, in infants with NEC but negative culture results, and in control infants (p < 0.01). These differences persisted throughout the 48-hour study period. Interleukin-6 levels were also significantly higher in nonsurvivors than in survivors (p < 0.001). In contrast, plasma TNF values were not consistently increased in any of the groups. We conclude that plasma interleukin-6 is a more reliable indicator of bacterial sepsis and NEC than plasma TNF and may identify infants who might benefit from immunotherapeutic strategies.
Continuity care clinic in obstetrics and gynecology.
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Chronic fatigue syndrome: a follow up study.
Forty-six of 47 patients diagnosed as having chronic fatigue and offered treatment four years previously were followed up. Twenty-nine patients were interviewed, three patients refused an interview, and information on the remaining 14 was obtained from their general practitioners. All the instruments used at interview had been used in the initial study. The long-term prognosis for patients with chronic fatigue syndrome who have initially responded to treatment is good. Spontaneous recovery in those who declined or who did not benefit from treatment is unlikely. Patients who continue to fulfil the criteria for chronic fatigue syndrome four years after they were initially diagnosed are likely to have had more somatic disorders, to have been more fatigued, and to have had a previous psychiatric history when they were initially assessed.
Randomized clinical trial of pressure-controlled inverse ratio ventilation and extracorporeal CO2 removal for adult respiratory distress syndrome.
The impact of a new therapy that includes pressure-controlled inverse ratio ventilation followed by extracorporeal CO2 removal on the survival of patients with severe ARDS was evaluated in a randomized controlled clinical trial. Computerized protocols generated around-the-clock instructions for management of arterial oxygenation to assure equivalent intensity of care for patients randomized to the new therapy limb and those randomized to the control, mechanical ventilation limb. We randomized 40 patients with severe ARDS who met the ECMO entry criteria. The main outcome measure was survival at 30 days after randomization. Survival was not significantly different in the 19 mechanical ventilation (42%) and 21 new therapy (extracorporeal) (33%) patients (p = 0.8). All deaths occurred within 30 days of randomization. Overall patient survival was 38% (15 of 40) and was about four times that expected from historical data (p = 0.0002). Extracorporeal treatment group survival was not significantly different from other published survival rates after extracorporeal CO2 removal. Mechanical ventilation patient group survival was significantly higher than the 12% derived from published data (p = 0.0001). Protocols controlled care 86% of the time. Average PaO2 was 59 mm Hg in both treatment groups. Intensity of care required to maintain arterial oxygenation was similar in both groups (2.6 and 2.6 PEEP changes/day; 4.3 and 5.0 FIO2 changes/day). We conclude that there was no significant difference in survival between the mechanical ventilation and the extracorporeal CO2 removal groups. We do not recommend extracorporeal support as a therapy for ARDS. Extracorporeal support for ARDS should be restricted to controlled clinical trials.
Facial and acoustic nerve preservation during excision of extracanalicular acoustic neuromas using the suboccipital approach.
The results are presented from a consecutive operative series of 62 acoustic neuromas in 60 patients following the introduction of improved neurophysiological monitoring techniques. Twenty-two patients had usable preoperative hearing. Thirty tumours were less than 2.5 cm diameter and 32 greater in size. Operation was via a 3-4-cm diameter retromastoid craniectomy. The internal auditory meatus was opened by an ENT surgeon (RM) using a drill and the facial nerve identified by stimulation. The tumour was then centrally evacuated by a neurosurgeon (MT/HC) using an ultrasonic aspirator, and the thin exterior part of the tumour carefully dissected off the nerves in or around the capsule with constant stimulation and monitoring of facial EMG, BSAEP and electrocochleography. A new type of stimulation probe has been designed and coupled to a stimulator/integrator/tone burst generator (SB) so that continuous immediate direct feedback to the surgeon is possible. A variable amplitude discriminator rejects baseline EMG (> 50 microV) and a gating circuit prevents stimulus artefact (during monopolar stimulation) from causing interference. By these means the VII nerve could be identified even when translucent and undefinable as a nerve bundle. Anatomical preservation was possible in 98% of VII nerves. Full facial function was present in 20 cases immediately postoperatively. Full delayed recovery occurred in 23 cases giving an eventual total in House Grade I of 69%. Seven other cases recovered to House Grade II. There was therefore 81% satisfactory facial nerve function. This percentage is exactly the same for larger and for smaller tumours. Anatomical preservation of the VIII nerve was achieved in 24/62 (39%) of the whole series and 11/16 (69%) of those with a hearing loss of < 50 dB. Functional preservation of hearing described as usable by the patient (< 65 dB) was achieved in 7/22 cases (32%), 3/13 (23%) in tumours < 2.5 cm and 4/9 (44%) in those > 2.5 cm diameter. Hearing preservation of < 50 dB in patients with preoperative hearing threshold < 50 dB and tumours of < 2.5 cm was 3/11 (27%). Monitoring by BSAEP and ECochG was technically unsatisfactory because the responses were affected by drilling and stimulation. Acoustic nerve preservation should be attempted in all cases with measurable hearing, regardless of tumour size.
Study of 45 pregnant opiate addicts in Dublin.
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Abundant expression of apoprotein E by macrophages in human and rabbit atherosclerotic lesions.
Previous studies have demonstrated the presence of apoprotein (apo) E protein and message in arterial lesions. To determine the source of the synthesized apoE, we performed simultaneous in situ hybridization and immunocytochemistry on human and rabbit atherosclerotic tissue. Studies of serial sections of aortic atherosclerotic lesions from humans and hypercholesterolemic New Zealand White rabbits and Watanabe heritable hyperlipidemic rabbits revealed a similar pattern of macrophage-specific apoE expression in the rabbit and human lesions. In early lesions of rabbit atherosclerotic tissue, in which many macrophages were present, there was abundant expression of apoE mRNA. Northern blot analyses of total mRNA obtained from arterial macrophage-derived foam cells, freshly isolated from ballooned, cholesterol-fed New Zealand White rabbits, demonstrated positive hybridization with an apoE-specific riboprobe. Western blot analyses of conditioned media from the isolated foam cells placed in culture for up to 24 hours demonstrated the presence of secreted apoE. These studies demonstrated that in atherosclerotic lesions, arterial wall macrophages synthesize and secrete apoE and probably account for most of the apoE synthesized in the atherosclerotic artery.