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Biomedical subjects

S McDonald

Publications and source records attributed to S McDonald.

At least 91 records · Page 5Linked to original sources
PubMed1994

Error types in ideomotor apraxia: a qualitative analysis.

Seventeen brain-damaged subjects with dominant hemisphere pathology and 24 matched control subjects were asked to perform simple familiar gestures under four conditions: (1) verbal command (pantomime), (2) imitation, (3) with the actual object, and (4) verbal command a second time. The subjects subsequently watched a video of an actor performing simple movements and decided whether or not these were performed accurately. The gestural production task was videoed and analyzed for error type. Error type remained consistent over the four task conditions, although subgroups of patients made different types of errors. One group of patients with Ideomotor Apraxia (IMA) made more errors but of the same type as the controls, i.e., movement-related errors and the use of "body part as object" (BPO). The second group made mainly substituted (i.e. unrelated) movements and perseverative errors. The second group of subjects was also poorer at discriminating incorrectly performed movements in the recognition task. BPO errors were commonly made by the control group and they were also chosen as correct in the recognition task. This indicated that use of BPO may reflect a convention in symbolising gestures rather than pathology. The performance of the IMA subjects was discussed in relation to current theories of the mechanisms underlying apraxia.

Adult↗
PubMed1994

An ethical dilemma: risk versus responsibility.

1. In the psychiatric community, two highly profitable diagnoses currently are filling psychiatric hospitals: dissociative disorder and multiple personality disorder. Certainly these patients need help, and psychiatric nurses are well-qualified to plan their scope of care. However, when the hospital reported on in this article exploited these diagnoses by encouraging practices that extended lengths of stay and restricted patient's rights, the nurses were forced to speak out as advocates for the patients. 2. The dissociative disorder unit housed 10 patients billed at an intensive care unit rate of $1,200 per day. One patient's average fee per day was $1,560; multiply this by 10 patients, and the hospital received $15,600 per day from this unit alone. 3. Financial calculation is not what nurses are used to thinking about; indeed, it somehow seems unbefitting to link nursing care with any mention of monetary gain. Yet, this is exactly the sort of information that nurses must have in order to understand how hospital politics may influence their situation.

Abreaction↗
PubMed1993

Combined Betaseron R (recombinant human interferon beta) and radiation for inoperable non-small cell lung cancer.

PURPOSE: Based on in vitro evidence of radiosensitization by Betaseron (beta-IFN), a Phase I/II study was undertaken to determine toxicity and response using combined radiation (RT) and B-IFN in patients with unresectable Stage III and nonsmall cell lung cancer. METHODS AND MATERIALS: Varying doses of beta-IFN(10 to 90 x 10(6) IU) were administered IV immediately preceding RT on the first three days of weeks 1, 3, and 5. The RT dose was 1.8 Gy/day, 5 days/week for a total of 54 or 59.4 Gy. RESULTS: Thirty-nine patients were entered, 32 of whom were evaluable. The median follow-up time at time of analysis was 60 months. Responses were based on CT scan. The response rate for the total group was 81% with 44% achieving complete response. Seventy-eight percent of patients with complete response survived a minimum of 21 months. Twenty-six patients had Stage III A/B disease with a median tumor size of 6.5 cm. and median survival was 19.7 months. The 5-year actuarial survival for this group was 31%, with a plateau persisting after 3 years. There were no treatment related deaths nor any event of life threatening toxicity. Of eight patients surviving 3-5 years, no long-term toxicity has been observed. Karnofsky indices were 90-100 and respiratory symptoms were minimal. CONCLUSION: beta-IFN is well-tolerated. Response and survival rates are sufficiently encouraging to warrant further investigation in a randomized trial which has been accepted as an RTOG study awaiting drug availability.

Adult↗
PubMed1993

Pragmatic language skills after closed head injury: ability to meet the informational needs of the listener.

Two closed-head-injured subjects and 12 non-brain-damaged controls explained a novel procedure to a blindfolded third person. Their productions were transcribed and scored by nine judges on ratings scales based on Grice's maxims of quantity and manner. The two closed-head injury (CHI) productions were significantly inferior to the controls, both being rated as disorganized, confusing, and ineffective. While one subject's production was considered overly repetitive, the other had too little detail. In order to specify, more exactly, the nature of the deficits, a cohesion analysis and an analysis of informational content were performed. The cohesion analysis suggested that the CHI productions were generally similar to the controls. The informational analysis was more revealing. Judgements of detail and repetitiveness were reflected in the number of new and repeated propositions. Errors in sequencing and inclusion of irrelevant propositions contributed to the disorganized and confusing nature of the texts. The results were interpreted within the framework of frontal lobe deficits in monitoring and regulation of performance.

Adult↗
PubMed1993

Pulmonary changes induced by combined mouse beta-interferon (rMuIFN-beta) and irradiation in normal mice--toxic versus protective effects.

This study in normal mice was undertaken to investigate possible enhancement of pulmonary toxicity by interferon-beta (IFN-beta) combined with single doses of irradiation. A pharmacokinetic study preceded the toxicity study to determine the optimal route and timing of IFN administration. Graded single doses of radiation were combined with graded doses of IFN. Pulmonary toxicity was determined using endpoints of alveolar surfactant and procollagen in lung lavage fluid at 7 days, breathing frequency, lethality and histology. Increased lethality was seen when IFN was combined with irradiation at 12.5 Gy vs. irradiation alone. This occurred between 20 and 30 weeks post treatment with no increased breathing frequency or surfactant release, suggesting independent mechanisms of injury. Increased breathing frequency after 40 weeks, usually associated with fibrosis, was less pronounced for IFN treated vs. irradiation only controls. Ultrastructural studies at 72 weeks suggest reduced fibrosis in lungs of IFN treated vs. irradiation only controls. Supporting this was the finding that Procollagen III, a biosynthetic precursor of collagen, was increased in the lavage fluid at 7 days for all radiation doses but decreased with the addition of IFN at 12.5 and 15 Gy. Interferons can act either as sensitizers or radioprotectors, depending on the biological system and type of interferon. Our study suggests that while IFN-beta may increase the acute effects of radiation in the mouse lung, some protection from radiation-induced fibrosis, possibly related to alteration of immune mechanisms, may exist.

Animals↗
PubMed1993

Human studies on abecarnil a new beta-carboline anxiolytic: safety, tolerability and preliminary pharmacological profile.

1. Abecarnil (isopropyl-6-benzyloxy-4-methoxymethyl-beta-carboline-3-carboxylate), a beta-carboline with high affinity for benzodiazepine receptors, was tested in healthy male subjects; single doses of abecarnil were given in five dosage levels (1 mg, 5 mg, 10 mg, 20 mg, 40 mg) and in a multiple dose study in four dosage levels (15 mg, 30 mg, 60 mg, 90 mg day-1) for 7 days. On two days following multiple dose treatment, placebo was given in single-blind conditions (follow-up). In each dosage level, in both studies drug was given to 10 subjects (7: verum, 3: placebo). 2. Safety and tolerability were evaluated by changes in vital signs, incidence and severity of adverse reactions and biochemical and haematological screening. Drug effects were estimated utilizing a bipolar visual analogue scale (poles: 'sleepy'-'alert') and a psychomotor task, the digit symbol substitution task. The pharmacokinetics of single and multiple doses were also determined in the multiple dose study. 3. Abecarnil was generally well tolerated. In the single dose study the most frequently reported side effects associated with abecarnil at high doses (20 and 40 mg) were dizziness, unsteady gait, and lack of concentration. A decrement in performance on the digit symbol substitution task was also observed in the two high dosage groups 20 mg and 40 mg. Evaluation of visual analogue scale ratings did not reveal a sedative effect even at higher doses. 4. In the multiple dose study the most frequently reported side effects during the treatment period were dizziness, unsteady gait, and lack of concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Radiation oncology residents' computer workstation.

We are investigating the feasibility of using the Macintosh computer as a workstation platform for radiation oncology residents because of its ease of use, graphics capability, and low cost. Hypercard was chosen as the programming environment because it easily mixes graphics, text, and control functions in an integrated screen display. Furthermore, it results in a system that can be relatively easily extended and customized by individual users with varying degrees of computer skills. We have developed several software modules in order to test the ability of this environment to support the demands of such a workstation. Modules created thus far include various clinical physics aids and tutorials, treatment planning guides, oncology databases, and others. The software runs on all Macintosh configurations, but calculation speeds are improved when a 68020 or greater processor is used. In general, we have been pleased with the implementation thus far. Graphics display capability is good, but design and entry of graphics have proved labor-intensive. Searching is fast and text is easily entered and manipulated. Finished modules can be customized with minimal computer training, but implementing complex new functions requires familiarity with Hypercard's programming language. New modules, once developed, are easily integrated into the workstation universe, suggesting that cooperative development of the workstation by multiple contributors is realistically achievable.

Computer Graphics↗
PubMed1992

A participative approach to organisation restructuring: a case study from the Silver Chain Nursing Association (Inc).

This case study examines the review of the corporate structure of the Silver Chain Nursing Association. The design and conduct of the review process and the issues are discussed in the context of recent research and the published experiences of other organisations undergoing similar changes. The review was pro-active in that the restructuring was carried out in anticipation of changes in the external environment (eg: increased service demand and decreased funding) and issues in the internal environment (eg: decreased flexibility of labour and a dilution of the service ethos). The significant feature of the review design was allowing employees to have an opportunity to define the issues requiring change; generate and evaluate opportunities for improvement; and recommend a new organisation structure. It is concluded that in a properly designed and managed process and provided with adequate information, employees are quite capable of making objective and well informed contributions about how their organisations can best operate. Participation appears to have facilitated better quality decisions and timely, acceptable implementation plans.

Community Health Nursing↗
PubMed1991

Proximal femoral allografts in revision hip arthroplasty.

We followed prospectively 69 patients with 78 proximal femoral allografts performed for revision of total hip arthroplasty for an average of 36 months (range 29 to 68). Large fragment proximal femoral allografts and cortical strut allografts were successful in 85%. Grafts smaller than 3 cm in length (calcar grafts) were clinically successful in 81%, but 50% underwent significant radiographic resorption. We conclude that large proximal femoral allografts and cortical strut allografts provide dependable reconstruction of bone stock deficiencies during revision total hip arthroplasty.

Adult↗
PubMed1991

The first double-blind, placebo-controlled trial of a partial benzodiazepine agonist abecarnil (ZK 112-119) in generalized anxiety disorder.

This is the first reported controlled trial of a partial benzodiazepine agonist, abecarnil, utilized in the treatment of generalized anxiety disorder (GAD). It was a sequential dose-finding study comparing 15-30 mg/day, 7.5-15 mg/day, and 3-9 mg/day to placebo for 3 weeks of treatment followed by abrupt discontinuation through placebo substitution. Although the two higher dose groups had high incidence of central nervous system (CNS) sedative adverse effects, the 3-9 mg/day group tolerated the medication well with no dropouts. The 3-9 mg/day group, in comparison to the two higher doses and placebo, demonstrated efficacy in global improvement ratings and Hamilton Anxiety Scale (HAM-A) scores. At Week 3, 61 percent of the abecarnil 3-9 mg/day group was rated as at least 50 percent improved on the HAM-A, compared to 30 percent of the placebo group. With abrupt discontinuation there were mild to moderate withdrawal symptoms and loss of efficacy in the two higher dose groups. However, in the 3-9 mg/day abecarnil group, there were few withdrawal symptoms and almost no loss of efficacy following discontinuation.

Adult↗