Biomedical subjects

P Lewis

Publications and source records attributed to P Lewis.

At least 73 records · Page 4Linked to original sources

PubMed1998

Living with a person who has Parkinson's disease: the spouse's perspective by stage of disease. Parkinson's Study Group.

The objective of this study was to examine the experience of spouses caregiving for their spouse with Parkinson's disease (PD) and to determine whether their experiences differed by stage of disease. By using a cross-sectional design and mail questionnaire data from 380 spouse caregivers across 23 sites of the Parkinson Study Group, key caregiver variables were examined by stage of PD. Three categories of variables--caregiver role strain (10 measures), caregiver situation (four measures), and caregiver characteristics (four measures)--were analyzed by using t tests with Bonferroni correction. Specific types and amounts of role strain accumulated as the disease progressed, and they differed significantly between stages (p < 0.05). In the caregiving situation, the mean number of caregiving tasks tripled by stage 4/5. Negative changes in lifestyle plus decreases in predictability in caregivers' lives increased significantly in late-stage disease (p < 0.05). Caregiver characteristics of physical health and preparedness did not significantly differ across stages of disease. Depression was significantly higher by stage 4/5. Mutuality, the positive quality of the relationship as perceived by the caregiving spouse, declined beginning at stage 2. Caregiver strain is experienced across all stages of PD and accumulates significantly as the disease progresses. This study defines types and amounts of strain by stage of disease, which will be helpful in designing formal intervention trials to provide more effective help for spouse caregivers.

Aged↗

PubMed1998

Rabies virus entry into endosomes in IMR-32 human neuroblastoma cells.

Early events in rabies virus entry into cultured IMR-32 human neuroblastoma cells were investigated. After adsorption of rabies virus to the cell surface in the cold and warming to 37 degrees C in the presence of tracers for early endosomes, rabies virus and tracers were localized by immunofluorescence microscopy. After 5 min, rabies virus colocalized with Lucifer Yellow, Texas Red-dextran, rhodamine-wheat germ agglutinin, and transferrin receptor in puncta in the cell body, neurites, and nerve terminals. Rabies virus did not colocalize with lysosomal glycoprotein. An acidotropic probe revealed that some of the virus-containing puncta were acidified. Rabies virus also colocalized with synapsin I, a synaptic vesicle marker, in swellings along processes, indicating some virus enters nerve terminals. Electron microscopy revealed the presence of rabies virus within irregular membrane compartments located near the cell surface in the cell body and neurites. The membrane of the virus particle was often continuous with that of the vacuole. It is concluded that rabies virus enters IMR-32 neuroblastoma cells by adsorptive endocytosis and that, shortly after entry, rabies virus is located within and fuses with acidic endosomes.

Adsorption↗

PubMed1998

Combined lung volume reduction and mitral valve reconstruction.

Combined lung volume reduction and mitral valve reconstruction was performed in a 66-year-old man with end-stage emphysema and severe mitral regurgitation. Quality of life, pulmonary function, 6-minute walk, echocardiographic degree of mitral regurgitation, and New York Heart Association heart failure classification all improved substantially. A lung volume reduction operation can safely be combined with complex cardiac operations for patients with disabling dyspnea of a multifactorial nature.

Aged↗

PubMed1998

B mode ultrasonography--spectrum of paediatric ocular disease.

BACKGROUND: Despite having appropriate sonographic equipment available many radiologists remain unfamiliar with B mode sonography of the eye. OBJECTIVE: This article reviews the advantages and disadvantages of B mode sonography of the paediatric eye. We illustrate the spectrum of eye abnormalities occurring in paediatric practice and the sonographic appearance of clinical entities for which sonography is appropriate. MATERIALS AND METHOD: We reviewed our experience of eye sonography within a paediatric radiology department over 8 years. A total of 212 sonographic examinations were performed on 206 eyes in 103 children, aged from 3 days to 16 years (mean 4.6 years). RESULTS: Sonography was well tolerated by the children, was a very useful imaging modality and was the only diagnostic imaging modality required in 94%. Supplementary computed tomography (CT) was performed in ten of 206 eyes (5%) and magnetic resonance imaging (MR) was performed in two of 206 eyes (1%). CONCLUSIONS: B mode sonography is a very useful imaging modality for suspected ocular or orbital pathology in children and is often the appropriate first line investigation following clinical evaluation. Radiologists familiar with sonography of the eye can provide valuable support to their ophthalmology colleagues.

Adolescent↗

PubMed1998

The experience of clients and informal caregivers with community health care services.

Persistent changes in long term care policy reform in Ontario prompted one home care program to undertake a multifaceted study to evaluate the effects of those changes. This article describes the qualitative component of the study examining perceptions of clients (persons with disabilities; adults over 80 and under 80 years of age) and of informal caregivers concerning their satisfaction with services and the impact of service delivery on their quality of life. Responses and descriptions of relevant perceptions and experiences varied with category of participant. Study findings revealed that satisfaction with services and concomitant quality of life depended upon the quality of communication with service providers.

Adult↗

PubMed1998

Rabies virus entry into cultured rat hippocampal neurons.

Rabies virus entry into cultured hippocampal neurons was investigated by immunofluorescence and electron microscopy. Hippocampal neurons were susceptible to rabies virus infection and became filled with viral antigen 1 day after infection. Infection was inhibited by the lysosomotropic agents chloroquine and ammonium chloride. To study entry, neurons were adsorbed with rabies virus at 4 degrees C and warmed to 37 degrees C for short periods of time prior to fixation and localization of viral antigen by immunofluorescence microscopy By 5 min at 37 degrees C, viral antigen was localized to puncta in the cell body and dendrites and in synapses along dendrites. Little viral antigen was present in axons. Cells adsorbed with rabies virus were incubated with tracers for early endosomes. The endocytic tracers or markers Lucifer Yellow, transferrin receptor, dextran, and wheat germ agglutinin co-localized with rabies virus, indicating that rabies virus enters an endosome compartment shortly after uptake. Rabies virus also co-localized with LysoTracker Red, an acidotropic probe, indicating that some of the virus-containing endosomes are acidified. Rabies virus also co-localized with synapsin I, a synaptic vesicle marker, in nerve terminals but did not co-localize with lysosomal glycoprotein. By electron microscopy, after adsorption of virus and warming for 10 min, virus particles were present in coated pits, coated vesicles, and vacuolar membrane compartments in processes and axon terminals. It is concluded that rabies virus enters the somatodendritic domain and axon terminals of cultured hippocampal neurons by adsorptive endocytosis and is located in endosomes shortly after uptake.

Animals↗

PubMed1998

Cell-free human immunodeficiency virus type 1 in breast milk.

Breast-feeding may be an important route of human immunodeficiency virus type 1 (HIV-1) vertical transmission in settings where it is routinely practiced. To define the prevalence and quantity of HIV-1 in cell-free breast milk, samples from HIV-1-seropositive women were analyzed by quantitative competitive reverse transcription-polymerase chain reaction (QC-RT-PCR). HIV-1 RNA was detected in 29 (39%) of 75 specimens tested. Of these 29 specimens, 16 (55%) had levels that were near the detection limit of the assay (240 copies/mL), while 6 (21%) had >900 copies/mL. The maximum concentration of HIV-1 RNA detected was 8100 copies/mL. The prevalence of cell-free HIV-1 was higher in mature milk (47%) than in colostrum (27%, P = 0.1). Because mature milk is consumed in large quantities, these data suggest that cell-free HIV-1 in breast milk may contribute to vertical transmission of HIV-1.

Adolescent↗

PubMed1998

Forgetting rates in neuropsychiatric disorders.

OBJECTIVE: Previous studies have attributed accelerated forgetting rates on recognition memory tasks to temporal lobe pathology, but findings in some patient groups may have been attributable to metabolic disruption. Findings in psychiatric disorders such as schizophrenia are conflicting. The purpose of the present study was to compare forgetting rates in patients with confusional states (post-electroconvulsive therapy (post-ECT), delirium), with those obtained in schizophrenic patients (with putative temporal lobe pathology), non-ECT depressed patients, and healthy controls. The findings could also be compared with previous reports in patients with head injury, focal structural lesions, and Alzheimer's dementia. METHODS: Two studies employed a picture recognition task to examine forgetting rates, the first between delays of 1 minute, 15 minutes, and 30 minutes, and the second between delays of 10 minutes, 2 hours, and 24 hours. RESULTS: There were no significant differences in forgetting rates between 1 minute and 30 minutes, but the ECT group showed accelerated forgetting between 10 minutes and 2 hours compared with healthy controls, associated with a rapid decline in "hit rate". This was not attributable to differential changes in either depression or severity of memory impairment. There were no differences in forgetting rates across the other subject groups. CONCLUSION: Post-ECT confusional state patients (similarly to "within post-traumatic amnesia" patients with head injury) show accelerated forgetting on a recognition memory task and, in this, they contrast with patients who have focal structural lesions or widespread cortical atrophy. Accelerated forgetting may reflect the effect of disrupted cerebral metabolism on either "consolidation" or memory "binding" processes.

Adult↗

PubMed1998

Air pollution and daily mortality in Sydney, Australia, 1989 through 1993.

OBJECTIVES: This study examined the effects of outdoor air pollutants in Sydney, Australia, on daily mortality. METHODS: Time-series analysis was performed on counts of daily mortality and major outdoor air pollutants (particulates, ozone, and nitrogen dioxide) in Sydney (1989 to 1993) with adjustment for seasonal and cyclical factors. Poisson regression was calculated with allowance for overdispersion and autocorrelation. The effects of lagging exposure by 0 to 2 days were assessed with single- and multiple-pollutant models. RESULTS: An increase in daily mean particulate concentration from the 10th to the 90th centile was associated with an increase of 2.63% (95% confidence interval 0.87 to 4.41) in all-cause mortality and 2.68% (0.25 to 5.16) in cardiovascular mortality. An increase in daily maximum 1-hour ozone concentration from the 10th to the 90th centile was associated with an increase of 2.04% (0.37 to 3.73) in all-cause mortality and 2.52% (-0.25 to 5.38) in cardiovascular mortality. An increase in the daily mean nitrogen dioxide concentration from the 10th to the 90th centile was associated with an increase of 7.71% (-0.34 to 16.40) in respiratory mortality. Multiple-pollutant models suggest that the effects of particulates and ozone on all-cause and cardiovascular mortality, and of nitrogen dioxide on respiratory mortality, are independent of the effects of the other pollutants. CONCLUSIONS: Current levels of air pollution in Sydney are associated with daily mortality.

Air Pollutants↗

PubMed1997

Positron emission tomography in male violent offenders with schizophrenia.

The FDG PET brain scans from 31 offenders with schizophrenia and schizoaffective disorder from a maximum security mental hospital were compared with those of normal controls (N = 6) in terms of relative FDG uptake in a range of regions covering frontal and temporal regions. The patient sample was divided into those who had a history of repetitive violent offending (RVO, N = 17) and those without a repetitive violent history (NRVO, N = 14) according to the violence rating of their pre-admission convictions. Reduced FDG uptake was noted at both the right and left anterior inferior temporal (R and L AIT) regions in NRVOs but only at LAIT in RVOs. NRVOs had significantly lower FDG uptake at RAIT than RVOs. The findings suggest that metabolic changes at AIT may be related to different patterns of violent offending in patients with schizophrenia.

Adult↗

PubMed1997

Multicentre CRC phase II trial of temozolomide in recurrent or progressive high-grade glioma.

PURPOSE: Patients with progressive or recurrent supratentorial high-grade gliomas were entered into a multicentre phase II trial to evaluate the efficacy and toxicity of temozolomide. METHODS: The treatment schedule was 150-200 mg/m2 per day orally for 5 days repeated every 28 days. Response evaluation was by a combination of neurological status evaluation (MRC scale) and imaging. RESULTS: Of 103 eligible patients enrolled, 11 (11%) achieved an objective response and a further 48 (47%) had stable disease. The median response duration was 4.6 months. Response rates were similar for anaplastic astrocytomas (grade III) and glioblastoma multiforme (grade IV) tumours. Predictable myelosuppression was the major toxicity. CONCLUSIONS: The observation of objective responses and tolerable side effects in this heterogeneous population of patients supports the further investigation of this agent in high-grade gliomas.

Adult↗

PubMed1997

Rabies virus infection of IMR-32 human neuroblastoma cells and effect of neurochemical and other agents.

IMR-32 human neuroblastoma cells are a continuous nerve cell line expressing neuronal nicotinic acetylcholine receptors. These cells were found to be susceptible to infection by rabies virus (CVS strain). After infection, viral antigen accumulated in the cell body in puncta and larger masses and spread out into the processes until at 3-4 days the entire cell was filled with antigen and lysed. A variety of chemical agents including cholinergic agonists and antagonists were tested for ability to inhibit infection of IMR-32 cells in a fluorescent focus assay. Agents found to inhibit infection were antibodies against the viral glycoprotein, gangliosides, a synthetic peptide of the neurotoxin-binding site of Torpedo acetylcholine receptor alpha1 subunit, alpha-bungarotoxin, and lysosomotropic agents. All other agents tested including other cholinergic ligands and synthetic peptides were not effective. Except for lysosomotropic agents, the agents which inhibited infection also inhibited attachment of virus to the cell surface. These results indicate that IMR-32 cells are a useful model in studying the interaction of a neurotropic virus with human neurons. The ability of alpha-bungarotoxin to inhibit infection suggests that neuronal alpha-bungarotoxin-binding receptors might serve as central nervous system receptors for rabies virus.

Antigens, Viral↗

PubMed1997

Use of store and forward technology for vascular nursing teleconsultation service.

Accurate assessment is critical in planning appropriate therapeutic management of a patient with a vascular wound. However, several factors may inhibit wound assessment by trained professionals or subspecialists. Multiple co-morbidities and lack of transportation and finances contribute to problems with access to specialty clinics for both rural and urban patients with vascular disease. To assess the application of telemedicine in meeting the needs of rural patients with vascular disease, the vascular nurse clinician of a regional medical network was incorporated into a telemedicine research project that used a still-image transmission system known as the Picasso telephone, which allows a diagnostic quality image to be transmitted over a regular telephone line. Telephone consultation between sender and receiver occurs simultaneously at the time of image transmission. Because images can be collected and stored for future reference, this technology is commonly called "store and forward" technology. The application of advanced technology in a rural health care environment has the potential to reduce costs for both patient and managed care insurance plans, allow for expert consultation from distant centers, and promote collegiality and learning among professionals.

Aged↗

PubMed1997

The effect of turning and backrub on mixed venous oxygen saturation in critically ill patients.

OBJECTIVE: To examine the effect of a change in body position (right or left lateral) and timing of backrub (immediate or delayed) on mixed venous oxygen saturation in surgical ICU patients. METHODS: A repeated-measures design was used to study 57 critically ill men. Mixed venous oxygen saturation was recorded at 1-minute intervals for 5 minutes in each of three periods: baseline, after turning, and after backrub. Subjects were randomly assigned to body position and timing of backrub. Subjects in the immediate-backrub group were turned and given a 1-minute backrub. Mixed venous oxygen saturation was measured at 1-minute intervals for 5 minutes at two points: after the backrub and then with the patient lying on his side. For subjects in the delayed-backrub group, saturation was measured at 1-minute intervals for 5 minutes at two different points: after the subject was turned to his side and after the backrub. RESULTS: Both position and timing of backrub had significant effects on mixed venous oxygen saturation across conditions over time. Subjects positioned on their left side had a significantly greater decrease in saturation when the backrub was started. At the end of the backrub, saturation was significantly lower in subjects lying on their left side than in subjects lying on their right side. The pattern of change differed according to the timing of the backrub, and return to baseline levels of saturation after intervention differed according to body position. CONCLUSIONS: Two consecutive interventions (change in body position and backrub) cause a greater decrease in mixed venous oxygen saturation than the two interventions separated by a 5-minute equilibration period. Turning to the left side decreases oxygen saturation more than turning to the ride side does. Oxygen saturation returns to clinically acceptable ranges within 5 minutes of an intervention. In patients with stable hemodynamic conditions, the standard practice of turning the patient and immediately giving a backrub is recommended. However, it is prudent to closely monitor individual patterns of mixed venous oxygen saturation, particularly in patients with unstable hemodynamic conditions.

Adult↗

PubMed1997