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Biomedical subjects

W Morrison

Publications and source records attributed to W Morrison.

At least 19 recordsLinked to original sources
PubMed1999

Muscle protection following motor nerve repair in combination with leukemia inhibitory factor.

Leukemia inhibitory factor (LIF) has been shown to stimulate growth of muscle and nerve cells. In this rat study, in which the nerve to the medial head of the gastrocnemius was divided and repaired and slow-release LIF was administered at the repair site, we evaluated recovery by measuring the force of muscle contraction and of muscle bulk. Thirty-five male Sprague-Dawley rats (325-375 g) were randomly divided into 5 different groups according to type of treatment: denervated, end-to-end nerve repair, end-to-end nerve repair with LIF, neurotization, and neurotization with LIF. The contralateral side served as a nonoperated control group. Leukemia inhibitory factor was administered for 28 days to the site of the nerve repair via an implanted osmotic infusion pump. Muscle mass and muscular function were evaluated at 6 weeks using electrophysiologic techniques. The medial gastrocnemius muscle mass of the repair + LIF group was greater than the repair-alone group. The peak twitch, relative twitch, relative tetanic, and tetanic forces generated from the repair + LIF group were also significantly higher than those in the repair-alone group. Although neurotization was almost as effective as end-to-end nerve repair for reinnervating muscle, LIF had no increased effect on neurotization. These data suggest that LIF protects muscular function and reduces denervation atrophy following end-to-end nerve repair.

Animals↗
PubMed1999

Will I make it through this choppy water? A psychological characteristic as a predeterminant factor to coping with multiple sclerosis.

The ability to cope with major stressors and adversity in our lives is as individual as the human experience. An unpredictable disease such as Multiple Sclerosis (MS) can demand major adjustments to one's lifestyle, employment, and personal relationships. Why is it that some sail smoothly through major upheaval in all of these realms despite the acquisition of significant physical disability while others are immobilized by seemingly trivial disruptions in their routine. How can we, as health professionals, assist those who are coping in a non-adaptive manner, to identify and implement more effective strategies. Does focused counseling early in the disease promote effective coping? Existing literature reviews coping with chronic illness, detailing the tools and strategies which individuals may use to manage stressors. This paper will build on this foundation of knowledge. How well you are determines how well you cope. The emphasis will be on "premorbid" personality traits which may be critical to coping. The author will critically examine the practicality of utilizing existing assessment tools for those at differing stages of MS and offer assessment guidelines for nurses working both with newly diagnosed and well-established disease. Suggestions for counseling techniques which may promote effective coping behaviors will be offered. How an individual copes with a chronic illness such as MS has implications for that person's family, social network and society at large. Those who become overwhelmed by a disease such as MS will stop working earlier, utilize more healthcare resources, and rate themselves as having poor quality of life. Nurses and other health professionals who have regular contact with those with MS may be able to influence this scenario.

Adaptation, Psychological↗
PubMed1998

Helical CT of calcaneal fractures: technique and imaging features.

Since the degree of comminution, fracture alignment, and articular congruity of intra-articular calcaneal fractures are important determinants in surgical treatment and patient prognosis, we review helical computed tomographic (CT) technique and features for detecting and assessing the extent of acute calcaneal fractures. Helical CT can be used to classify these fractures and facilitate the surgeon's understanding of the anatomy and position of the fracture components in all orthogonal planes independently of the patient's condition, foot placement in the CT gantry, or other injuries.

Calcaneus↗
PubMed1996

Depression and multiple sclerosis.

The objective of the present study were (1) to ascertain the lifetime risk of a depression in a representative group of multiple sclerosis (MS) patients, (2) to assess the morbidity risks for depression among first-degree relatives of these MS patients, and (3) to compare these familial risks for first-degree relatives of MS patients with those for first-degree relatives of a primary depression population, i.e., depression but no MS. We psychiatrically evaluated 221 MS patients (index cases) using a structured clinical interview for the DSM-III-R and calculated the rate and lifetime risk of depression for these index cases using the product limit estimate of survival function. We obtained psychiatric histories for all first-degree relatives of index cases, and we calculated morbidity risks for depression for these relatives using the maximum likelihood approach and compared the risks using the likelihood ratio tests. Index cases had a 50.3% lifetime risk of depression. Morbidity risks for depression among first-degree relatives of index cases were decidedly lower when compared with morbidity risks among first-degree relatives of the reference population. Although there appears to be a very high rate of depression among MS patients, the data for their first-degree relatives do not support a clear genetic basis for this depression, or at least the same genetic basis that probably operates within families when depression occurs in the absence of MS.

Adolescent↗
PubMed1996

Betaseron: a breakthrough treatment for multiple sclerosis.

Multiple sclerosis (MS) is the most common cause of disability in young adults; in Canada, it affects 1 in 1,000 people. A chronic and complicated demyelinating autoimmune disorder of the central nervous system, MS has no known cure. Indeed, there has been no effective treatment until recently.

Adjuvants, Immunologic↗
PubMed1995

Urinary myelin basic protein-like material as a correlate of the progression of multiple sclerosis.

In the multicenter, randomized, placebo-controlled trial of alternate-day injections of recombinant interferon beta-1b in relapsing-remitting multiple sclerosis (MS), urine specimens were collected periodically from all patients (n = 64) in two of the clinical test sites over the 2 years of the study. Urine specimens were also collected over two consecutive 24-hour periods from 43 patients from a third center. Urine samples were assayed for their content of myelin basic protein-like material (MBPLM), the level of which was correlated with clinical changes, cranial magnetic resonance imaging results, and the development of progressive disease. Concordant changes in creatinine values affected some of the relationships of MBPLM. The level of urinary MBPLM correlated with a chronic progressive course and with the number of lesions and the total lesion area on cranial magnetic resonance images. A rise in the level of urinary MBPLM appeared to antedate the clinical transition from a relapsing-remitting to a chronic progressive course. By chance, the randomized entry of patients led to significant differences in urinary MBPLM levels among the three treatment groups, thus precluding correlation studies of treatment effects. However, the patient group from which 24-hour specimens were collected showed that the patients with relapsing-remitting MS changing to a chronic progressive course, and more specifically, those patients with chronic progressive MS receiving placebo, had the highest values of urinary MBPLM. These findings indicate that urinary MBPLM may offer an objective test and possibly serve as a surrogate marker for detecting or predicting the failure of remission or the transition to a progressive phase of MS.

Analysis of Variance↗
PubMed1995

Morphologic change in rabbit femoral arteries induced by storage at four degrees Celsius and by subsequent reperfusion.

PURPOSE: Cold-stored arteries function well as microvascular autografts, but little is known of the morphologic changes that occur in them during cold storage or of further changes during reperfusion. METHODS: In part A of the study, rabbit femoral arteries were stored at 4 degrees C for up to 6 months. In part B rabbit femoral arteries were stored at 4 degrees C for up to 6 months, inserted as end-to-end autografts into contralateral femoral arteries, and reperfused for 24 hours. Tissue was examined by histologic study, transmission and scanning electron microscopy, histochemical study, immunohistochemical study, and tissue culture. RESULTS: Cell viability declined gradually at 4 degrees C, so that by 4 weeks no viable cells remained. However, the extracellular framework and elastic lamellae remain intact. If cold-stored arteries are reinserted as autografts for 24 hours, this accelerates breakdown of necrotic cells and reduces the thickness of the medial wall and internal elastic lamina but does not alter the extracellular framework. CONCLUSIONS: Cold storage results in acellular vascular grafts with intact extracellular frameworks. After 24 hours reperfusion there is no major change to the extracellular framework.

Actins↗
PubMed1995

Role of leukaemia inhibitory factor (LIF) in rat peripheral nerve regeneration.

The cytokine leukaemia inhibitory factor (LIF) favours the survival and growth of axons in vitro. The efficacy of this factor in the in vivo model has been the aim of this study. Following nerve transection and immediate entubulation repair in the rat sciatic nerve, this study demonstrated that (1) LIF promotes the growth of a population of axons of greater cross-sectional area after 6 and 12 weeks in comparison to either saline (negative control) or basic fibroblast growth factor (bFGF) (positive control), (2) LIF improves the nerve conduction velocity of regenerating axons, (3) LIF has a positive effect on skeletal muscle mass following nerve repair, (4) the benefits of LIF on skeletal muscle appear to be somewhat independent of reinnervation as similar observations are made where there is no growth of a tissue bridge within the tube, and (5) the effects of LIF seem to be potentiated by the addition of fibronectin.

Animals↗
PubMed1994

Trials and tribulations: patients' perspectives of the Betaseron study.

The University of British Columbia Multiple Sclerosis (MS) Clinic was one of 11 North American sites involved in the double-blind, placebo-controlled phase III trial of Betaseron in relapsing-remitting MS. UBC participants as a unique sub-study site which required a rigorous evaluation every six weeks for the first two years. Each visit included extensive blood studies, neurological and physical exams by separate physicians. Magnetic Resonance Imaging (MRI) and evaluation by a research nurse. In addition, participants learned to administer the study medication subcutaneously every second day and keep extensive diaries of possible side effects, concomitant medications, neurological signs and symptoms, and incidental environmental events. The attrition rate was low (8%) despite the gruelling requirements of the study. As patients completed their course of therapy (and before unblinding took place) they were asked to complete a simple questionnaire about various aspects of the study. Questions explored their reasons for participation, helpfulness of preparatory information, positive and negative aspects during the trial, and their "guess" at what they were receiving. This paper will summarize the results of the questionnaires and offer suggestions for consideration when organizing long-term outpatient clinical trials.

Adjuvants, Immunologic↗
PubMed1994

Environmental triggers in multiple sclerosis. Fact or fallacy?

Multiple Sclerosis (MS) is an autoimmune, demyelinating disease of the central nervous system. In the early, most common course of the disease there are seemingly random attacks or exacerbations usually followed by partial or complete recovery. It has long been postulated that environmental events such as infection, emotional stress, or trauma play some role in triggering exacerbations, worsening of the disease, or even the onset of MS. Indeed there have been monetary awards by the courts based on possible influence on the disease following motor vehicle accidents. This paper will describe a prospective study undertaken at the UBC MS Clinic evaluating the impact of infection, emotional stress, and physical trauma on the course of the disease in 50 relapsing-remitting patients participating in the Betaseron trial. During the first two years of the clinical trail this cohort kept diaries documenting environmental "events". The participants were evaluated clinically and with Magnetic Resonance Imaging (MRI) every six weeks. The potential triggers or events are correlated with disease activity seen on MRI, relapse occurrence and disease progression according to the neurological exam. The results of the study and their implications for patient counselling will be presented.

Environment↗
PubMed1993

Motor nerve biopsy: feasibility and safety.

Motor nerve biopsy was attempted on 19 occasions in 18 patients. Nerve tissue was obtained in 16. The nerves biopsied included those to the anconeus (4 times), palmaris longus (6), flexor sublimus (1), triceps (2), extensor carpi radialis (1), quadriceps (1) and gastrocnemius (1). Attempts to biopsy the radial nerve, the nerve to plantaris and the left common peroneal nerves failed in 2 patients. The lengths of nerve obtained varied from 1 to 3 cm, and from 1-5 fasciculi were present in the specimens. Sufficient material for both electron microscopy and teasing was present in 11. No patient experienced increased weakness, but one had transient paraesthesiae in the distal forearm following biopsy of the nerve to the palmaris longus. We conclude that motor nerve biopsy as described is both feasible and safe. The nerve to the palmaris longus, where that muscle was present, provided the optimum specimen for pathological studies.

Adult↗
PubMed1991

Myelin basic protein specific T cell lines and clones derived from the CNS of rats with EAE only recognize encephalitogenic epitopes.

The epitope specificities of myelin basic protein (BP) specific T cell lines derived from the spinal cords (SC) and lymph nodes (LN) of rats with experimental autoimmune encephalomyelitis (EAE) were compared. To induce EAE, Lewis rats were immunized with guinea pig (GP)-BP and complete Freund's adjuvant. Mononuclear cells from the SC and LN of these animals proliferated in response to BP and the purified protein derivative (PPD) of mycobacterium. After initially being cultured in growth medium, SC mononuclear cells had an enhanced response to BP and lost their response to PPD. LN cells cultured in identical conditions lost their response to both BP and PPD. LN-derived BP specific cell lines recognized only two epitopes of GP-BP: an encephalitogenic epitope in residues 72-89 and a non-encephalitogenic epitope in residues 43-68. SC-derived BP specific cell lines and clones recognized the 72-89 epitope and a second encephalitogenic epitope contained in residues 87-99 but not the non-encephalitogenic 43-68 epitope. Unlike those from LN, BP-specific T cell lines and clones derived from the CNS appear to recognize only encephalitogenic epitopes, including epitopes not recognized by LN lines.

Animals↗
PubMed1991

Exposure of fertile chicken eggs to microwave radiation (2.45 GHz, CW) during incubation: technique and evaluation.

A multi-mode cavity constructed of 22-gauge perforated galvanized steel with a horn irradiator was used to expose chicken embryos to microwave (MW) radiation during incubation. The MW exposure system was placed within an environmental chamber. Mean +/- standard error of mean (SEM) power level was 3.6 +/- 0.02 mW/cm2 and mean egg specific absorption rate was 0.8 mW/g per mW/cm2. Mean temperature of the MW-exposed eggs was 37.5 +/- 0.9 degrees C as monitored by a Luxtron fluoroptic thermometer. Non-irradiated eggs were incubated at 37.5 +/- 0.1 degrees C and 55% relative humidity. There was no significant different in percent fertile eggs hatched between eggs exposed to MW radiation during incubation or eggs incubated conventionally (82.9% and 87.7%, respectively).

Animals↗
PubMed1987

The gatekeeping funnel: tracking a major PSA campaign from distribution through gatekeepers to target audience.

This article presents the gatekeeping funnel as a model of the process that a public service announcement (PSA) goes through from distribution until it reaches its target audience. Process measures such as bounceback postcards, the Broadcast Advertisers Report (BAR), and analysis of audience response are suggested as ways of monitoring this funneling process. The model is then applied to the National Cancer Institute's PSA campaign designed to promote cancer prevention awareness. Three waves of PSAs were distributed between March 1984 and May 1985. Two of these waves of PSAs were targeted to the general public and the third wave was targeted to black audiences. Bounceback postcards, BAR data, and the Cancer Information Service (CIS) call data exemplify the gatekeeping funnel model described in the article. When the messages were distributed, they had the potential of reaching 170 million adults with televisions. BAR data show that the gatekeeping function narrowed the number of people potentially exposed to the messages to 24 million, or 14% of the total. Yet only 144,000 people, or less than one-tenth of 1% responded to the messages by calling the CIS number and asking about cancer prevention. This analysis may help PSA campaign planners to develop more realistic expectations for message effects.

Black or African American↗
PubMed1985

[Microsurgical repair of the vas deferens. Apropos of 115 cases].

The demand for the reversal of vasectomy in the treatment of sterility has been increasing over the past decade. Microsurgery is acknowledged to be the best non-traumatic procedure for this reconstruction. This article reviews 115 patients treated by microvasovasostomy over a period of six years. Evaluation of the results shows 76% of patients with a positive seminal analysis, and 52% informed the authors that their partners were pregnant. In addition to the technical aspects (i.e. the non-traumatic manipulation of tissues using microsurgical procedures) the titer of antisperm bodies in the patient's serum and seminal plasma seems to play some part in the recovery of fertility.

Follow-Up Studies↗
PubMed1981

Long-term association of N-(phosphonacetyl)-L-aspartate with bone.

By means of enzymatic and autoradiographic techniques, it has been demonstrated that, 24 hr after a single dose of the antitumor amino acid N-phosphonacetyl-L-aspartic acid (PALA), (400 mg/kg i.p.; 1.15 mmol/kg) to C57BL x DBA/2 F1 mice, the agent accumulates in bone to a concentration of approximately 400 microM; this is 3000 times greater than the Ki of PALA for its target enzyme, aspartate carbamoyltransferase. However, disproportionately low inhibition of enzyme activity was demonstrated in homogenates of bone from these recipients, suggesting that the drug was sequestered from its target in this tissue. Autoradiography of sections of femoral shafts from mice treated with 14C-labeled drug demonstrated that autoradiogram density due to [14C]PALA equivalents was confined to the bony matrix, with no label above background resolvable in bone marrow. Following in vivo administration of PALA (400 mg/kg i.p.), the half-life of the drug in the bone was approximately 23 days. In vitro, with equilibrium dialysis at pH 7.4, it was demonstrated that: (a) normal pulverized and decalcified bone bound PALA with capacities of 3.5 nmol/mg and 0.1 nmol/mg bone, respectively, at a PALA concentration of 5 mM; (b) binding of PALA to normal bone reached saturation at a concentration of 200 mM; and (c) PALA functions as a solubilizer of bone at concentrations above this. Since administration of PALA was shown to produce long-lasting inhibition of aspartate carbamoyltransferase in liver and tumor and since its ultimate half-life in the plasma of mice, following a single 400-mg/kg administration of the drug, is 8 days, it is suggested that bone serves as a reservoir from which PALA is released at a slow rate into plasma and other tissues.

Animals↗