Search PubMed⌕ Search

Biomedical subjects

S Lewis

Publications and source records attributed to S Lewis.

At least 163 records · Page 9Linked to original sources
PubMed1998

Use of a neonatal blood pressure cuff to monitor blood pressure in the adult finger--comparison with a standard adult arm cuff.

BACKGROUND: There are few suitable methods for monitoring blood pressure continuously (or intermittently) for research in adult stroke patients, who are ill but do not justify invasive intensive care monitoring. METHOD: We tested a neonatal arm blood pressure in adults by placing it on the forefinger ("finger cuff"). We compared the repeatability of the finger cuff with blood pressure measured by a standard adult arm cuff using the oscillometric technique in 168 ambulatory outpatients attending a cerebrovascular disease clinic. RESULTS: The mean difference between sequential mean blood pressure readings with the finger cuff was 0.55 mm Hg (95% confidence interval (CI) -14.36 to 15.47 mm Hg), and for the arm cuff was 3.31 mm Hg (95% CI -23.33 to 16.71 mm Hg). Measurements made with the arm cuff were shown to affect subsequent arm cuff readings made within a few minutes of the first. The mean difference between the finger cuff and arm cuff mean blood pressure readings was 0.03 mm Hg (95% CI -26.07 to 26.14 mm Hg) and agreement was better when the blood pressure was measured with the finger cuff first rather than the arm cuff. However, although there was no difference in the mean blood pressure recordings both systolic and diastolic blood pressure measurements differed systematically between arm and finger cuff. CONCLUSION: The reproducibility of sequential blood pressure measurements made with the finger cuff was better than with the arm cuff. The performance of the finger cuff compared with that of the arm cuff was sufficiently good to encourage use of the finger cuff in research involving automatic intermittent monitoring to observe sequential blood pressures over time in stroke patients. However, measurements of systolic and diastolic pressure were not the same with the two cuffs and further work on calibration of the finger cuff would be useful.

Adolescent↗
PubMed1998

The EsthetiCone abutment: three-year results of a prospective multicenter investigation.

The EsthetiCone abutment, designed for subgingival restorative margins, makes it possible to achieve ideal esthetics, function, and predictability. This study included 200 EsthetiCone abutments placed in 50 partial or complete edentulous patients participating in a multicenter study performed in Europe and the United States. The patients were followed for 3 years and the marginal bone level of the implants was determined from intra-oral radiographs. During the follow-up period, a total of 9 of patients were withdrawn from the study. Based on the remaining patients, a total of 164 EsthetiCone abutments (82%) were evaluated through the 3-year follow-up visit. Only 1 EsthetiCone abutment failed during the study period, resulting in a cumulative success rate of 99.2% in the maxilla and 100% in the mandible after 3 years. No bone loss due to the usage of short abutment collars (1 mm) was seen in this study. The marginal bone resorption during the 3-year period did not exceed 1 mm as a mean neither for the 1 mm nor the higher abutments when analyzed separately. During the follow-up period, few complications were reported and they were all easily rectified without compromising the treatment success. The outcome of this study indicates that safe long-term and esthetically good results can be achieved when the Brånemark implants are loaded with EsthetiCone abutments. The reported need of a 3 mm peri-implant sulcus with an animal model was not confirmed with patients in this study.

Alveolar Bone Loss↗
PubMed1998

Classification of asthma severity: should the international guidelines be changed?

BACKGROUND: International guidelines recommend that, in addition to symptoms and medication requirements, measurements of forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) are necessary for the objective assessment of asthma severity. The guidelines suggest that parity exists between measurements of FEV1 and PEF when expressed as percentage of predicted normal values, and that asthma severity can be classified as mild, moderate or severe on the basis of FEV and PEF measurements of > 80%, 60-80% and < 60% of predicted values, respectively. OBJECTIVE: To determine the relationship between measurements of FEV1 and PEF when expressed as percentage predicted values. METHODS: A total of 1198 paired measurements of FEV1 and PEF were obtained from the medical records of a random sample of 25 adult asthmatic patients attending a hospital-based chest clinic. Measurements of lung function were expressed as a percentage of predicted normal values, using the European Respiratory Society prediction equations for PEF and FEV1. For the individual paired measurements, the mean differences between PEF and FEV percentage predicted were calculated. Measurements of lung function were used to determine asthma severity with <60%, 60-80%, and >80% predicted FEV1 and PEF values representing severe, moderate and mild asthma, respectively. The proportion of paired measurements in which differences in classification resulted from the use of FEV1 or PEF percentage predicted values was then calculated. RESULTS: In asthma of differing severity, there was considerable variability between measurements of FEV1 and PEF when expressed as percentage predicted values; calculation of the FEV1% predicted resulted in lower values than those of the PEF percentage predicted, with a mean difference of -17.2% (95% CI -16.3%, -18.1%). There was agreement in classification of asthma severity in only 49.9% (598/1198) of paired measurements. Different prediction equations, while variably altering the degree of misclassification, did not correct the basic differences in the assessment of asthma severity dependent on the use of FEV or PEF. CONCLUSION: FEV1 and PEF values, expressed as percentage predicted, are not equivalent. Pending further evaluation, the authors suggest that published asthma guidelines should avoid the assumption of parity between these two measurements.

Adolescent↗
PubMed1998

Survival rates among children with severe neurologic disabilities.

BACKGROUND: This study was done to determine survival rates in subpopulations of severely neurologically disabled children who reside in pediatric skilled nursing facilities and to compare these survival rates with those in previously published studies. METHODS: Data were collected at three pediatric skilled nursing facilities over the 1986 to 1996 decade. The total study population numbered 447. We studied in detail six groups of the most severely disabled children and correlated their survival rates with clinical parameters and the presence of other significant diseases. RESULTS: The survival rates in our six groups of severely disabled children were significantly better than those previously reported. In group 1, our 8-year survival rate was 66%, as compared with 5% in the previous study. In group 2, our 8-year survival rate was 89%, versus 22% in the previous study. We obtained better survival rates in all six groups studied, irrespective of the analysis including children less than 1 year old, between 1 year and 15 years old, or more than 15 years old. The most significant determinant for reduced survival was the presence of other significant diseases. Those with other significant diseases had a 10-year survival rate of 45%, whereas those who were relatively healthy had a survival rate of 90%. Patients who received gastrostomy tube feedings had a better 10-year survival rate than those fed by nasogastric tube (78% vs 41%). This difference was independent of the presence of other significant medical diseases. CONCLUSIONS: Our results show substantially better survival rates than those previously reported. These improved results are most likely related to much more intense medical management of severely disabled children in skilled nursing facilities than at home or in other residential settings. Our study also showed a significantly better survival rate for those fed by gastrostomy tube as compared with nasogastric tube.

Adolescent↗
PubMed1998

BioViews: Java-based tools for genomic data visualization.

Visualization tools for bioinformatics ideally should provide universal access to the most current data in an interactive and intuitive graphical user interface. Since the introduction of Java, a language designed for distributed programming over the Web, the technology now exists to build a genomic data visualization tool that meets these requirements. Using Java we have developed a prototype genome browser applet (BioViews) that incorporates a three-level graphical view of genomic data: a physical map, an annotated sequence map, and a DNA sequence display. Annotated biological features are displayed on the physical and sequence-based maps, and the different views are interconnected. The applet is linked to several databases and can retrieve features and display hyperlinked textual data on selected features. In addition to browsing genomic data, different types of analyses can be performed interactively and the results of these analyses visualized alongside prior annotations. Our genome browser is built on top of extensible, reusable graphic components specifically designed for bioinformatics. Other groups can (and do) reuse this work in various ways. Genome centers can reuse large parts of the genome browser with minor modifications, bioinformatics groups working on sequence analysis can reuse components to build front ends for analysis programs, and biology laboratories can reuse components to publish results as dynamic Web documents.

Animals↗
PubMed1998

A pilot study of the effect of mechanical ventilation and heat exchange on house-dust mites and Der p 1 in New Zealand homes.

We have examined the effect of reducing relative humidity (RH), with inbuilt mechanical ventilation and heat-exchange (MVHE) units, on house-dust-mite (HDM) counts and allergen levels, in a pilot study of 10 Wellington dwellings. Recent international prevalence studies in adults and children have confirmed a high prevalence of asthma in New Zealand. Sensitivity to HDM is common among the general population, and HDM is the major allergen associated with asthma. Recent studies of allergen levels have confirmed high concentrations of Der p 1 in the domestic environment. While humidity was significantly reduced in those dwellings fitted with ventilation units, no systematic effect on mites or Der p 1 was observed during the study period. When the reductions in humidity were examined in the context of the time spent below the critical equilibrium humidity (CEH), the intervention led to RH values below the CEH for only 39% of the total of 24-h periods for which measurements were made. Reducing RH by means of MVHE in New Zealand domestic dwellings does not lower humidity sufficiently, or long enough, to have any measurable effect on HDM populations.

Allergens↗
PubMed1998

Failure of hairpin-ended and nicked DNA To activate DNA-dependent protein kinase: implications for V(D)J recombination.

V(D)J recombination is initiated by a coordinated cleavage reaction that nicks DNA at two sites and then forms a hairpin coding end and blunt signal end at each site. Following cleavage, the DNA ends are joined by a process that is incompletely understood but nevertheless depends on DNA-dependent protein kinase (DNA-PK), which consists of Ku and a 460-kDa catalytic subunit (DNA-PKCS or p460). Ku directs DNA-PKCS to DNA ends to efficiently activate the kinase. In vivo, the mouse SCID mutation in DNA-PKCS disrupts joining of the hairpin coding ends but spares joining of the open signal ends. To better understand the mechanism of V(D)J recombination, we measured the activation of DNA-PK by the three DNA structures formed during the cleavage reaction: open ends, DNA nicks, and hairpin ends. Although open DNA ends strongly activated DNA-PK, nicked DNA substrates and hairpin-ended DNA did not. Therefore, even though efficient processing of hairpin coding ends requires DNA-PKCS, this may occur by activation of the kinase bound to the cogenerated open signal end rather than to the hairpin end itself.

Animals↗
PubMed1998

Recovery from visuospatial neglect in stroke patients.

OBJECTIVES: To describe the natural recovery of visuospatial neglect in stroke patients and the distribution of errors made on cancellation tests using a standardised neuropsychological test battery. METHOD: A prospective study of acute (< seven days) patients with right hemispheric stroke. Patients identified with visuospatial neglect were followed up for three months with monthly clinical and neuropsychological testing RESULTS: There were 66 patients with acute right hemispheric stroke assessed of whom 27 (40.9%) had evidence of visuospatial neglect. Patients with neglect, on admission, had a mean behavioural inattention test (BIT) score of 56.3, range 10-126 (normal>129). Three of the subtests identified errors being made in both the right and left hemispaces. During follow up, recovery occurred across both hemispaces, maximal in the right hemispace. Recovery from visuospatial neglect was associated with improvement in function as assessed by the Barthel score. At the end of the study period only six (31.5%) patients had persisting evidence of neglect. On admission the best predictor of recovery of visuospatial neglect was the line cancellation test (Spearman's rank correlation r=-0.4217, p=0.028). CONCLUSION: The demonstration of errors in both hemispaces has implications for the theory that neglect is a lateralised attentional problem and is important to recognise in planning the rehabilitation of stroke patients.

Activities of Daily Living↗
PubMed1998

A quantitative study of the emotional outcome of people caring for stroke survivors.

BACKGROUND AND PURPOSE: Although the physical and, to a lesser extent, emotional outcome of stroke survivors has been well documented, there are far fewer data relating to the outcomes of those who care for them. We aimed to describe the outcome of those caring for stroke patients and to identify both patient and caregiver factors that are associated with poor caregiver outcomes. METHODS: As part of a randomized trial to evaluate a stroke family care worker, we identified 417 patients (67% of all referrals to our institution). We followed up 376 survivors of whom 246 identified a caregiver at a 6-month follow-up interview. The patients and caregivers were asked to complete 2 measures of emotional distress ( 30-item General Health Questionnaire [GHQ-30] and Hospital Anxiety and Depression [HAD] Scale). A regression analysis was used to identify factors that were independently associated with poor caregiver outcomes. RESULTS: Fifty-five percent of responding caregivers scored more than 4 on the GHQ-30, indicating that emotional distress is common in this group. Caregivers were more likely to be depressed if the patients were severely dependent (P<0.01) or emotionally distressed themselves (P<0.01). Female caregivers reported more anxiety (median HAD=8) than male caregivers (median HAD=5; P<0.01) but caregivers' levels of anxiety were not so clearly related to the patients' degree of physical disability as their levels of depression. Caregivers suffered more emotional distress if the patients had been dependent before their strokes. CONCLUSIONS: These data may help to identify those caregivers at greatest risk of poor emotional outcomes and thus help in the planning of trials and delivery of interventions aimed at preventing or treating distress among caregivers.

Activities of Daily Living↗
PubMed1998

Increasing prevalence of wheeze and asthma in Nottingham primary schoolchildren 1988-1995.

The prevalence of asthma in children has increased substantially in many countries in recent decades, but it is not clear how much this trend has continued into the 1990s. This study aimed to estimate the current prevalence of asthma and wheeze in British primary schoolchildren and to determine whether there has been any increase in the prevalence of these conditions since 1988. The prevalence of self-reported wheeze and asthma was measured by parental questionnaire in 22,968 children aged 4-11 yrs attending primary schools in the Nottingham area of England in 1995, and these estimates were compared with data from a subsample of the same schools in 1988. In 1995, wheezing ever was reported in 24.0% of children, wheezing in the past year in 15.1% and diagnosed asthma symptomatic in the past year in 8.8%. All measures have increased in prevalence since 1988, in absolute terms by 7.7% for wheeze ever, by 2.6% for wheeze in the past year and by 2.7% for asthma. The increases were greater in females than males, but did not vary with age. In conclusion, the prevalence of asthma has continued to rise in British schoolchildren since the late 1980s, particularly in females, and across all ages.

Asthma↗
PubMed1998

Brain changes in schizophrenia. Volumetric MRI study of families multiply affected with schizophrenia--the Maudsley Family Study 5.

BACKGROUND: Structural brain abnormalities have been reported in schizophrenia. We tested the hypothesis that these abnormalities represented a marker for the genetic liability to schizophrenia in a sample of people with schizophrenia and their relatives from families multiply affected with the disorder. METHOD: We compared 31 people with schizophrenia, 57 relatives and 39 unrelated control subjects. Volumetric measurement of brain structures was carried out using stereological principles from three-dimensional reconstructed magnetic resonance images. RESULTS: Subjects with schizophrenia had larger lateral ventricles than their relatives and the normal control subjects. Relatives who were 'presumed obligate carriers' had larger left lateral ventricles than other relatives and the control subjects. Subjects with schizophrenia showed smaller whole brain and cerebellar volumes and larger lateral ventricles than their age- and gender-matched unaffected siblings. CONCLUSIONS: In families multiply affected with schizophrenia lateral ventricular enlargement distinguishes people with schizophrenia and presumed obligate carriers from other relatives and unrelated control subjects. These changes may be a marker for a genetic liability to schizophrenia.

Adult↗
PubMed1998

Combination therapy for HIV: the effect on inpatient activity, morbidity and mortality of a cohort of patients.

We set out to quantify the changes in HIV-related morbidity and mortality associated with the clinical use of antiretroviral therapy via prospectively collected patient-related events (admissions, bed days, deaths, WHO stage 3 and 4 events and drug costs) on all HIV patients known to the Regional Infectious Disease Unit (RIDU) from 1 January 1987 to 31 December 1996. The introduction of zidovudine monotherapy in 1987 for those with AIDS was associated with a subsequent decline of inpatient activity for 2 years: in 1989 there was a 23% reduction in bed days but only a 6% reduction in admissions. A further dramatic decline of patient-related events in those with AIDS was noted during 1996 following the introduction of combination therapy, a 39% reduction in admissions, 44% reduction in bed days, 54% reduction in stage 4 events, 33% reduction in WHO stage 3 events and 40% reduction in the death rate. Reductions were also observed for patients without AIDS including a 42% reduction in the rate of patients developing AIDS. Similar reductions were noted when the patients were classified by immunological instead of clinical status although data for 1997 suggest an increase in patient-related activity for those with CD4 counts >200 cells/microl possibly as a result of low levels of anti-HIV therapy. The introduction of combination therapy for HIV has to date led to a minimum saving of one inpatient bed per 100 patient years which helped defray the cost of combination therapy. Although we cannot imply causality from an observational study, dramatic reductions in patient-related activity were associated with the introduction of combination therapy into clinical practice. The ultimate extent and duration of this effect cannot as yet be predicted and caution is required since similar reductions were noted with zidovudine therapy which were unfortunately time limited.

Anti-HIV Agents↗
PubMed1998

Prevalence of adult asthma symptoms in relation to climate in New Zealand.

We conducted an ecological study linking prevalence of adult asthma symptoms with climate in the 93 New Zealand general electorates. For each electorate, the 12-month period prevalence of self-reported asthma symptoms was determined using a random sample of adults aged 20-44 on the 1991 New Zealand electoral roll. Long-term average climate was estimated using a national climate database and a geographic information system. Asthma prevalence was calculated within quartiles of the exposure variables. Independent effects of climate variables were assessed using linear regression models, with adjustment for confounding by climate, social deprivation, and geographic variables. There was a statistically significant association between asthma prevalence and mean temperature, with the lowest quartile of mean temperature having an approximately 2% lower asthma prevalence. After adjusting for confounding, there was a monotonic increase in asthma prevalence within quartiles of temperature. The results of this study are in agreement with other research suggesting a lower prevalence of asthma at low temperatures. Although on short (day-to-day) time scales, low temperatures may have a direct effect resulting in acute exacerbations of asthma symptoms, warmer average temperatures are associated with increased asthma prevalence. The reasons for this are unclear, although it is possible that on longer term (annual) time scales, higher temperatures are associated with higher levels of allergen exposure.

Adult↗
PubMed1998

Individual cognitive-behavioural interventions in early psychosis.

BACKGROUND: Cognitive-behavioural treatments have previously been explored in the treatment of chronic psychotic problems, but recently, the effectiveness of these treatments has been investigated with regard to recent onset and acute psychosis. METHOD: The literature relating to cognitive-behavioural treatments in psychosis is explored and the application of the approach to recent onset psychosis is described in detail. RESULTS: There appears to be a growing body of evidence that the advances made in the treatment of people with chronic treatment resistant psychosis can be similarly applied to people with recent onset and acute psychosis. CONCLUSIONS: Cognitive-behavioural treatments are feasible with recent onset psychotic patients although further evaluation of their effectiveness is necessary.

Antipsychotic Agents↗