Cholesterol-lowering agent in men without CHD.
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Adult↗
Biomedical subjects
P Millard
Publications and source records attributed to P Millard.
Geriatric-patient flow-rate modelling.
We consider the application of a three-compartment mathematical model using difference equations in discrete time to model the flow of patients through departments of geriatric medicine. It has been shown empirically that the time spent in hospital since admission may be described by a two-term mixed-exponential distribution. Previous work has explained this empirical finding in terms of a two-compartment model of geriatric in-patient behaviour where the two compartments are acute/rehabilitative and long-stay care. Our model extends this approach by considering patients released from geriatric departments and their subsequent length of stay in the community. We have therefore, two states of patient behaviour while in hospital: (i) patients can be admitted to the acute-rehabilitative state, from which they may die or be released back into the community; (ii) patients can be admitted to the long-stay state, from which they eventually die. The community state currently has only one state, from which patients may be readmitted back into the geriatric department or they may die. The model may then be used to estimate the average numbers and lengths of stay for short-term and long-term patients and the average number and length of stay in the community for released patients, allowing for a significant improvement in the forecasting of future bed requirements to aid the planning of geriatric departments.
Aged↗
Role of nitrogen remobilization from old leaves for new leaf growth of Eucalyptus globulus seedlings.
Six-month-old Eucalyptus globulus Labill. seedlings were grown in sand culture irrigated with a nutrient solution containing 6.0 mol N m(-3) for 3 months (November-January). Before rapid growth began in February, seedlings were repotted and irrigated with either 6.0 mol N m(-3) (High-N treatment) or 1.0 mol N m(-3) (Low-N treatment). Seedlings were analyzed during the subsequent flush of growth to determine the role of old leaves, and in particular the leaf protein Rubsico, as a source of N for new leaf growth. During spring growth, the N content of old leaves of High-N seedlings decreased with decreasing leaf dry weight, although there was no change in leaf number. In High-N seedlings, the net loss of N from old leaves provided less than 10% of the N used for new leaf growth, and the new leaves quickly became the dominant sink for N. In contrast, in Low-N seedlings, the net loss of N from old leaves provided 44% of the N used for new leaf growth. During the period of spring growth, the amount of soluble proteins recovered from old leaves of Low-N seedlings dropped, but there was no change in the content of either Rubisco or chlorophyll. The photosynthetic capacity of old leaves remained constant throughout the study period, and there was no evidence that N was remobilized from Rubisco.
Journal Article↗
The effect of stay in a maternity waiting home on perinatal mortality in rural Zimbabwe.
A hospital-based cohort study was carried out in a district hospital in Zimbabwe to evaluate the effect of a maternity waiting home on perinatal mortality. Information on antenatal risk factors, use of antenatal care, access to the hospital and stage of labour on arrival was collected for each woman delivering at the hospital during the period 1989-1991 (n = 6438). Women who stayed in the maternity waiting home had a lower risk of perinatal death compared to women who came directly from home to the hospital during labour. The crude relative risk of perinatal death for the women coming from home was 1.7 (95% confidence interval (CI) 1.1-2.6; P < 0.05). After adjusting for the effect of potential confounding variables, the relative risk decreased to 1.5 (95% CI 0.95-2.5, P = 0.07). However, when the analysis was restricted to women with antenatal risk factors there was a significant 50% reduction in the risk of perinatal death for the women who stayed at the maternity waiting home compared to women who came from home during labour (adjusted relative risk 1.9; 95% CI 1.1-3.4; P < 0.05). The use of maternity waiting homes has the potential to reduce perinatal mortality in rural areas with low geographic access to hospitals and merits further evaluation.
Adolescent↗
Stochastic models for geriatric in-patient behaviour.
Departments of geriatric medicine engage in two distinct forms of clinical activity: acute/rehabilitative and long-stay care. These are organizationally distinct and have very different resource needs. Current hospital planning models, however, assume that patients all move through the system at the same rate, thereby ignoring this effect of inherent heterogeneity in patient behaviour. The present paper describes the movement of patients through geriatric hospitals by a two-stage continuous-time Markov model, where the stages represent acute/rehabilitative and long-stay patients respectively. Patients are initially admitted to the first stage, from which they may depart from the system, by death or discharge, or move into the second stage, from which they eventually depart by death or discharge (unlikely). Admissions are modelled in two ways: either as replacements for departures or as a Poisson stream. Expressions for the distribution and movement of numbers of patients are derived and evaluated for data from a number of hospitals. Such an approach has the advantage, over previous crude models, of taking into account different types of patients and introducing variability, thus making it possible to extract variances as well as means of numbers of geriatric patients requiring hospital care.
Aged↗
Relationships between nutrient supply, nitrogen partitioning and growth in young Sitka spruce (Picea sitchensis).
Budget studies have shown that internal cycling may contribute a large proportion of the annual nutrient supply required to support new growth in trees. Use of budgets to quantify internal cycling only quantifies the net transfer of nutrients within the plant. Differential partitioning of remobilized nutrients and current nutrient uptake could lead to errors in the interpretation of results from these studies. We have quantified the dynamic relationships among tree growth, nutrient uptake and internal cycling by labeling the current uptake of N in trees that received contrasting amounts of nutrient. Two-year-old seedlings of Sitka spruce (Picea sitchensis (Bong.) Carr.) were grown in sand culture in a greenhouse for one year. The trees received nutrients in a balanced solution at either a high (high-RAR) or a low (low-RAR) relative addition rate throughout the experiment. Current N uptake was labeled with (15)N from April 13 to July 25. Thereafter, trees were re-potted in clean sand and unlabeled N applied until November 13. Overall growth was sustained for approximately 10 weeks before treatment effects were observed. Initially, no differences in the partition of growth or remobilized N occurred, although partition of current uptake favored the roots of plants in the low-RAR treatment. After 6 weeks, the partition of both growth and remobilized N altered in favor of roots of plants in the low-RAR treatment. Nutrient supply had no effect on the amount or rate of N remobilization. No evidence was found to suggest that N taken up in the current season and partitioned to preexisting shoots or roots is remobilized late in the season to support growth of new shoots. However, some trees in the high-RAR treatment exhibited a second flush of growth later in the season that was partially sustained by remobilization of (15)N from current shoots formed earlier in the season. Use of (15)N demonstrated differential partitioning of current uptake and remobilized N. The results highlight the limitations of simple budget studies for quantifying internal cycling.
Journal Article↗
Mucosal lichen sclerosus/lichen planus overlap syndromes.
Lichen sclerosus and lichen planus affecting cutaneous sites are easily distinguishable clinical. Clinical signs on mucosal sites, however, may not allow differentiation between these diseases, and reliance is frequently placed on histopathological findings. We report a series of seven patients with clinical evidence of coexisting vulval lichen sclerosus and lichenoid oral lesions. All patients had vulval biopsies, and four had oral biopsies. Histology of all the vulval biopsy specimens showed features consistent with lichen sclerosus. Two of these patients developed vulval intraepithelial neoplasia during the course of their disease, and one progressed to a well-differentiated squamous carcinoma. Histology of the oral lesions showed features that were predominantly those of lichen planus. There are, however, few reports of histologically proven oral lichen sclerosus. Variations in histopathological descriptions of lichen sclerosus, depending on duration of disease, have been reported, particularly with regard to the position of the inflammatory infiltrate in relation to the dermo-epidermal junction. We believe that these patients may have oral lichen sclerosus, or at the very least make up a distinctive group who need to be identified and followed up, as their risk of oral dysplasia is unknown.
Aged↗
Response of T-beta CD8+ lymphocytosis-associated neutropenia to G-CSF.
Only limited data are reported on the response to granulocyte-colony stimulating factor (G-CSF) of large granular lymphocytosis-associated neutropenia. We report features of such a case who developed a suppurating leg ulcer following a dog bite. G-CSF was used to increase the neutrophil count, allowing the ulcer to be successfully skin grafted.
Female↗
Modelling in-patient bed usage behaviour in a department of geriatric medicine.
The flow of patients through geriatric hospitals has been previously described in terms of acute and long-stay states where the bed occupancy at a census point is modelled by a mixed exponential model. Using data for sixteen years the model was fitted to successive annual census points, in order to provide a description of temporal trends. While the number of acute patients has remained fairly stable during the period, the model shows that there has been a decrease in the number of long-stay patients. Mean lengths of stay in our geriatric hospital before death or discharge have decreased during the study period for both acute and long-stay patients. Using these fits of the mixed exponential model to census data, a method is provided for predicting future turnover of patients. These predictions are reasonably good, except when the turnover patterns go through a period of flux in which assumption of stability no longer holds. Overall, a methodology is presented which relates census analysis to the behaviour of admission cohorts, thus producing a means of predicting future behaviour of patients and identifying where there is a change in patterns.
Aged↗
Storage and internal cycling of nitrogen in relation to seasonal growth of Sitka spruce.
Three-year-old clonal cuttings of Picea sitchensis (Bong.) Carr. were grown for two years (1988-1989) in sand irrigated with a nutrient solution containing either 1.0 mol N m(-3) (low N) or 6.0 mol N m(-3) (high N) NH(4)NO(3). In 1988, all the N provided was enriched with (15)N to 4.95 atom % (labeled N). In 1989, N was supplied with (15)N at natural abundance (unlabeled N). The recovery of unlabeled and labeled N in new foliage was used to quantify the internal cycling of N. In the high-N treatment, trees had two flushes of shoot growth and a period of rapid root growth, which coincided with the second flush of shoot growth in August. The timing of root growth and the first flush of shoot growth was similar in the low-N treatment, but there was no second flush of shoot growth and a greater proportion of biomass was recovered in roots. By November 1989, the root/needle dry matter ratio was 1.95 for the low-N trees and 1.36 for the high-N trees. Nitrogen was stored overwinter in roots and current-year needles. During the first six weeks of growth in the spring of 1989, stored N was remobilized for new foliage growth. Subsequent growth depended on root uptake of N. Remobilization of stored N was apparently not affected by the current N supply, because the amount of unlabeled N recovered in foliage produced in 1988 was the same for both N treatments. During 1989, the proportion of (15)N remobilized from roots relative to that from leaves produced in 1988 was greater in low-N trees than in high-N trees. In the autumn of both years, there was rapid uptake of N into roots and current-year needles. The effects of N supply on tree growth and nitrogen use efficiency are discussed in terms of the capacity for both N storage and internal cycling.
Journal Article↗
Bullous and haemorrhagic lichen sclerosus with scalp involvement.
We describe a patient who developed a generalized blistering eruption due to lichen sclerosus and who was observed to have scalp involvement. Both are unusual manifestations of this disease which merit consideration. Lichen sclerosus is an uncommon disease that most frequently affects the external genitalia of perimenopausal women. The aetiology is unknown. Approximately 20% of affected patients have extragenital lesions that present as small, ivory, shiny round macules or papules that later become atrophic; extragenital lesions are generally asymptomatic. Bullous and haemorrhagic forms may occur but these are generally localized and reports of extensive or generalized involvement are rare. We describe an elderly woman with generalized bullous lichen sclerosus. As an incidental finding, she was observed to have lichen sclerosus affecting her scalp. This has rarely been described and it would appear that she is the third reported case of scalp involvement.
Aged↗
Hypoglycaemia masquerading as a stroke.
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Aged↗
Throughput in a department of geriatric medicine: a problem of time, space, and behaviour.
Over a period of 16 years, the annual admissions to the Merton part of the St George's Department of Geriatric Medicine increased, then decreased, before rising again. Examination of the mean length of stay and bed turnover indicated that patient management was continually changing. However, this was not confirmed by a percentile analysis of the pattern of length of stay after admission. Present plans for hospital medical services for elderly people are based on the hypothesis that length of stay shortens linearly with time. The results of this study do not support this hypothesis. They do, however, imply the need to regularly review the policies for the medical care of elderly people.
Acute Disease↗
Antenatal village stay and pregnancy outcome in rural Zimbabwe.
DESIGN: Comparative study of pregnancy outcome for parturients who had stayed in an antenatal village and for those admitted directly from the community. SETTING: A rural hospital in Zimbabwe. OUTCOME MEASURES: Birthweight, perinatal mortality and degree of obstetrical intervention. RESULTS: Women who stayed in the antenatal village experienced better pregnancy outcome than women admitted directly from the community. Birthweight was greater, perinatal mortality lower, and obstetrical intervention less often required in the antenatal village group. CONCLUSIONS: Lack of randomisation, differences between the two groups in antenatal risk factors, and lack of information relating to socio-economic status suggest that generalisations beyond the specific case be made cautiously.
Adult↗
Inhibition of NK and ADCC activity by antibodies against purified cytoplasmic granules from rat LGL tumors.
Highly purified preparations of cytoplasmic granules from transplantable rat large granular lymphocyte (LGL) tumor lines (rat natural killer (RNK) tumors) were used to immunize rabbits. Antibodies from these animals gave two precipitin lines with granule extracts in Ouchterlony experiments. They reacted with at least four different bands on nitrocellulose blots of SDS gels of LGL granule proteins. By immunofluorescence, specifically adsorbed antigranule antibodies did not recognize LGL or T cell surface antigens but reacted with the cytoplasmic granules in permeabilized RNK tumor cells as well as with normal rat LGL. These same antisera showed little or no reactivity with a panel of other cells, including peripheral blood T cells, thymocytes, macrophages, and EL-4 tumor cells. F(ab')2 preparations of these antigranule antibodies completely blocked granule-mediated lysis of both SRBC and nucleated targets, while control F(ab')2 preparations from rabbits immunized with EL-4 granules or TNP-KLH showed no significant inhibition of this cytolytic activity at the same antibody concentration. Anti-granule F(ab')2 preparations specifically inhibited (greater than 75%) rat natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) activities in a dose-dependent manner but did not effect cytotoxic T cell activity. Pretreatment of either effectors or targets by these antibodies had no effect. Anti-granule F(ab')2 preparations, at concentrations showing strong inhibition of lysis, did not inhibit the binding of LGL to YAC-1 or Ab-coated P815 targets. These results demonstrate that a granule component(s) is necessary for the lytic activity of LGL in both NK and ADCC and provide the first direct evidence that a secretory event involving these granules is part of the lytic process.
Animals↗
Evidence for an accelerated rejection response to cardiac allografts in antigen-treated mice which then resolves.
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Animals↗
The role of cytoplasmic granules in cytotoxicity by large granular lymphocytes and cytotoxic T lymphocytes.
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Animals↗
Prediction of the conformation and antigenic determinants of the V-sis viral oncogene product homologous with human platelet-derived growth factor.
In an extensive study involving unification of secondary structure prediction methods to predict peptide backbone angles, folding simulations, and interactive graphics we have calculated conformations for a 160 residue p28sis protein fragment. We demonstrate that the state of the art is sufficient to aid artificial vaccine design.
Antigens, Viral↗