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Biomedical subjects

B Cooper

Publications and source records attributed to B Cooper.

At least 109 records · Page 6Linked to original sources
PubMed1991

The epidemiology of primary degenerative dementia and related neurological disorders.

Observation of cytopathological similarities between the changes of Alzheimer-type dementia, Parkinson's disease and motor neuron disease, as well as of some degree of clinical association between these conditions, has led to the suggestion that all three belong to a common class of degenerative neurological disorders, each of which as a rule first becomes manifest when age-related neuronal attrition is superimposed on subclinical damage caused by environmental noxae earlier in life. The importance of this model lies in its potential relevance to prevention. The epidemiological data reviewed here suggest that, while the three disease groups are all strongly linked with ageing, there may be major differences between their patterns of occurrence in populations, which make it doubtful if the same environmental pathogens are responsible in each instance. The most plausible unifying hypothesis at present is that the predisposing neuronal damage can be caused by a number of widely distributed metallic neurotoxins, each of which has a tendency to pick out specific areas or cell groups within the CNS and thus to give rise to distinct though overlapping clinical syndromes. The evidence bearing on this and other causal hypotheses is, however, still tenuous because of the scarcity of empirical data. Population-based case-control and cohort studies are called for, as part of a co-ordinated research endeavour.

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PubMed1991

Panniculitis in an immunocompromised patient.

We present a patient in whom histoplasmosis panniculitis developed during steroid therapy for pancytopenia secondary to myelodysplasia. Although the cutaneous manifestations of disseminated histoplasmosis are rare, we review them because of the increasing numbers of organ-transplant patients, as well as other patients with immunodeficiency, including acquired immune deficiency syndrome, in whom the risk of this unusual presentation of histoplasmosis must be considered.

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PubMed1991

Study of the definition of nosocomial infections (SDNI). Research Committee of the Association for Practitioners in Infection Control.

If nosocomial infections are to be used as clinical indicators of quality, their definitions must be accurate. To assess validity and reliability of definitions of nosocomial infection, a study was conducted in two groups of U.S. hospitals. Group A consisted of a stratified, random sample of 715 hospitals and excluded those that are part of the National Nosocomial Infections Surveillance System. The 112 NNIS hospitals were surveyed separately in group B. Both groups used the same instrument, consisting of 36 case studies simulating patients' charts. Content and construct validity were formally tested and demonstrated. Six case studies were presented for each of the four major NI sites and for community-acquired or no infection. The pooled hospital response was 48% (396/827). The pooled number of individual responders whose data were used in the analysis was 469. Their overall mean score was 84%, and the score for correctly identifying any NI was 83%. Both groups were best at identifying urinary nosocomial infections (Group A = 92%, Group B = 93%) and poorest for no infection (Group A = 62%, Group B = 75%). Group A responders had significantly higher scores if they were certified, had a baccalaureate or higher degree, had taken a formal infection control course, had worked in infection control for greater than or equal to 2 years, or had worked full time in infection control in a greater than or equal to 200-bed hospital that was affiliated with a medical school (all p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Centers for Disease Control and Prevention, U.S.↗
PubMed1991

Stroke rehabilitation: Australian patient profile and functional outcome.

A prospective, multi-institutional, population based study identified 1274 non-surgical stroke admissions to all hospitals in a major Australian city during 1984. The demographic and diagnostic profile and the nature of functional recovery of all 258 first stroke survivors who were referred for inpatient rehabilitation are presented. The median duration of rehabilitation stay was 49 days. The mean functional independence score, as measured on a modified Barthel Index at admission was 44, compared with 78 on discharge, a mean improvement of 34. Stair climbing had the lowest mean value on admission (12), while bowel control had the lowest residual deficit on discharge (95). The stroke study group was representative of the unimpaired aged population in all respects except ethnicity, where differences are attributed to age. The variables identified as significant are; side and severity of paralysis, age and sex, marital status and ethnicity. Stroke rehabilitation outcome was not influenced by etiology, site of lesion, arterial distribution, occupation or education.

Activities of Daily Living↗
PubMed1991

The prevalence of dementia in Europe: a collaborative study of 1980-1990 findings. Eurodem Prevalence Research Group.

To obtain age- and gender-specific estimates of the prevalence of dementia in Europe and to study differences in prevalence across countries, we pooled and re-analysed original data of prevalence studies of dementia carried out in some European countries between 1980 and 1990. The study followed these steps: census of existing datasets, collection of data in a standardized format, selection of datasets suitable for comparison, comparison of age and gender patterns. From the 23 datasets of European surveys considered, 12 were selected for comparison. Only population-based studies in which dementia was defined by DSM-III or equivalent criteria and in which all subjects were examined personally were included. Studies in which institutionalized subjects were not investigated were excluded. Age- and gender-specific prevalences were compared within and across studies and overall prevalences were computed. Although prevalence estimates differed across studies, the general age- and gender-distribution was similar for all studies. The overall European prevalences for the five-year age groups from 60 to 94 years, were 1.0, 1.4, 4.1, 5.7, 13.0, 21.6 and 32.2%, respectively. In subjects under 75 years the prevalence of dementia was slightly higher in men than in women; in those aged 75 years or over the prevalence was higher in women. The prevalence figures nearly doubled with every five years of increase in age.

Adult↗
PubMed1991

Properties of high-threshold mechanoreceptors in the oral mucosa. I. Responses to dynamic and static pressure.

1. Mechanical response properties of high-threshold mechanoreceptors (HTMs) of the goat oral mucosa were determined by single-unit recording from the palatine and alveolar nerves and from the trigeminal ganglion. The following observations were made. 2. HTMs of the oral mucosa could be separated into two subgroups on the basis of their threshold to mechanical stimulation. Intense pressure receptors (IPRs) comprised a group of A-delta afferents with thresholds of 2-16 g. Mechanonociceptors (MNs) comprised a group of relatively slowly conducting afferents (A-delta and C-fibers) with a higher threshold range (16-300 g). 3. In most instances, MNs lacked pressure-transducing capacity. Tests of reactivity to dynamically or statically applied stimuli revealed that significant functions were rarely fit between MN activity and pressure (4/20 cases). 4. IPRs differed from MNs by their pressure-transducing properties. The afferent response interval was in inverse proportion to the applied pressure. Significant pressure interval functions were fit in 16/20 cases. The relationship between pressure and response interval was best described by power functions. 5. Tests of reactivity to dynamically or statically applied stimuli revealed that IPRs preferred static pressure. Tighter fits and steeper slopes were observed in power functions fit to data generated by statically applied stimuli (mean fitted function, dynamic test: LnISI = -0.97 LnP + 3.4; mean fitted function, static test: LnISI = -1.6 LnP + 4.71). 6. Pressures-frequency thresholds (PFTs), asymptotes (PFAs), and mean response intervals (MRIs) were determined for IPRs from the static test series. The first two values are the pressures that produce the lower and upper limits of response frequency of mucosal HTMs (mean PFT, 1.48 N/mm2; mean PFA, 3.34 N/mm2). The MRI (28 ms) is simply computed from the function. When PFTs and PFAs are combined with activation threshold and power functions, they provide a relatively complete description of the range and form of reactivity of the IPR of the oral mucosa.

Animals↗
PubMed1991

Properties of high-threshold mechanoreceptors in the goat oral mucosa. II. Dynamic and static reactivity in carrageenan-inflamed mucosa.

1. We have previously described two classes of high-threshold mechanoreceptors (HTMs) of the oral mucosa of the goat. Mechanonociceptors (MNs) had very high thresholds (16-300 g) and were poor transducers of pressure. Intense pressure receptors (IPRs) had thresholds from 2 to 16 g and were good transducers of pressure. After carrageenan inflammation (CI) we observed mechanical sensitization in both classes of HTMs. The characteristics were as follows. 2. Sensitization of MNs was manifested as qualitative shifts in the capacity to encode intense pressure. MNs that were unable to code intensity before CI acquired pressure coding properties after treatment with carrageenan. Qualitative shifts in coding capacity were suggested by the greater proportion of MNs coding in preinflamed (10 of 14) compared with noninflamed tissue (8 of 25 cases). Improved afferent reactivity was directly observed, in additional experiments, in which MNs were characterized in normal tissue before the injection of carrageenan into the mucosa. In five of six cases, either qualitative or quantitative improvements were observed. In control experiments, improved reactivity was observed in one of six cases. 3. Sensitization in IPRs was manifested as both qualitative and quantitative improvement in intensity coding properties. Power functions fit to individual IPRs indicated sensitization for most mucosal afferents after inflammation. Carrageenan induced decreases in the mean response interval, pressure-frequency threshold (PFT), and pressure-frequency asymptote (PFA), and decreases in variability of functions fit to units sampled from preinflamed and noninflamed tissue (n = 23). Experiments were also conducted in which units were characterized before and after carrageenan treatment. In 7 of 10 cases, injection of carrageenan into the oral mucosal led to improved dynamic and/or static reactivity. Injection of vehicle led to changes in reactivity in one of five cases. 4. Carrageenan induced decreases in activation thresholds only when afferent receptive fields fell into restricted tissue zones. Large shifts in activation thresholds were observed for five of five (3 MNs and 2 IPRs) units in the sulcal zone of the incisal papilla (IP). In contrast, activation thresholds increased or remained the same in 11 of 12 units (10 IPRs and 3 MNs) with receptive fields in the medial or ventral tissue zones. Changes in activation threshold evolved slowly after carrageenan injection and required 1-2 h to develop. Rapid changes in activation threshold were also observed in a limited number of cases (3). These threshold shifts were unrelated to carrageenan inflammation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

The crystal structure of human muscle aldolase at 3.0 A resolution.

The three-dimensional structure of fructose-1,6-bisphosphate aldolase from human muscle has been determined at 3.0 A resolution by X-ray crystallography. The active protein is a tetramer of 4 identical subunits each of which is composed of an eight-stranded alpha/beta-barrel structure. The lysine residue responsible for Schiff base formation with the substrate is located near the centre of the barrel in the middle of the sixth beta-strand. While the overall topology of the alpha/beta-barrel is very similar to those found in several other enzymes, the distribution of charged residues inside the core of the barrel seems distinct. The quaternary fold of human muscle aldolase uses interfacial regions also involved in the subunit association of other alpha/beta-barrel proteins found in glycolysis, but exploits these regions in a manner not seen previously.

Fructose-Bisphosphate Aldolase↗
PubMed1990

Efficiency, effectiveness, and duration of stroke rehabilitation.

This prospective multicenter study identifies the variables significant in the prediction of rehabilitation efficiency, achievement of rehabilitation potential and duration of rehabilitation stay in 258 persons with a first stroke admitted to comprehensive inpatient rehabilitation in Brisbane, Australia, during 1984. All three dependent variables were poorly predicted, with only 17% of the variance in rehabilitation efficiency, only 30% of the variance in achievement of rehabilitation potential, and only 22% of the variance in duration of rehabilitation stay explained. Unlike other reports, we considered most of the major medical (side of paralysis, stroke etiology, site of the lesion, arterial distribution affected, etc.), rehabilitative (initial Barthel Index score, interval from stroke onset to acute-care hospital admission, interval from hospital admission to rehabilitation commencement, neurologic measures, etc.), and demographic (age, years of education, occupation, ethnicity, etc.) variables. The high proportion of unexplained variance is likely to be due to nonmedical factors influencing the selection of patients for rehabilitation.

Analysis of Variance↗
PubMed1989

Improving the sensitivity of the Barthel Index for stroke rehabilitation.

The Barthel Index is considered to be the best of the ADL measurement scales. However, there are some scales that are more sensitive to small changes in functional independence than the Barthel Index. The sensitivity of the Barthel Index can be improved by expanding the number of categories used to record improvement in each ADL function. Suggested changes to the scoring of the Barthel Index, and guidelines for determining the level of independence are presented. These modifications and guidelines were applied in the assessment of 258 first stroke patients referred for inpatient comprehensive rehabilitation in Brisbane, Australia during 1984 calendar year. The modified scoring of the Barthel Index achieved greater sensitivity and improved reliability than the original version, without causing additional difficulty or affecting the implementation time. The internal consistency reliability coefficient for the modified scoring of the Barthel Index was 0.90, compared to 0.87 for the original scoring.

Activities of Daily Living↗
PubMed1989

Imaging of small cell carcinoma using 131I-labelled antibodies to vasopressin associated human neurophysin (VP-HNP)

Preliminary studies are reported on the use of 131I-labelled antibodies against vasopressin associated human neurophysin to image tumors in patients with small cell carcinoma of the lung (SCCL). The rabbit polyclonal antibodies used in these studies were affinity purified on columns of neurophysin-Sepharose. Patients were pre-screened for the presence of neurophysin producing tumors by plasma RIA. Six patients who screened positive received approximately 1 mCi/70 kg body weight of radioiodinated antibody preparation, and scintigraphy was subsequently performed at 24 h, 48 h, and 72 h using a subtraction technique based on simultaneous imaging with radiopharmaceutical agents labelled with technetium-99m. Tumor was clearly demonstrated at 72 h in all five patients who had measurable lesions at the time of study, while no positive image was noted for one patient in complete clinical remission. Since approximately 70% of all SCCL patients have neurophysin-producing tumors, our findings suggest that neurophysin antibodies may be effectively used to scan tumors in a majority of patients with SCCL.

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