Search PubMed⌕ Search

Biomedical subjects

J Grace

Publications and source records attributed to J Grace.

At least 37 records · Page 2Linked to original sources
PubMed1999

Olanzapine in dementia with Lewy bodies: a clinical study.

OBJECTIVES: Dementia with Lewy bodies (DLB) is now a well-recognized form of dementia in which psychosis and behavioural disturbance are common. Treatment with conventional neuroleptics is often very poorly tolerated. Olanzapine, a newly introduced atypical neuroleptic which binds to multiple receptor types with relatively low affinity for D2 receptors, may be a useful treatment option in DLB. MAIN OUTCOME MEASURES: The Behavioural Pathology in Alzheimer's Disease Rating Scale, The Neuropsychiatric Inventory, Unified Parkinson's Disease Rating Scale and The Webster Disability Scale. DESIGN: We present the results of eight DLB patients with associated psychotic and behavioural difficulties. All patients were given olanzapine 2.5-7.5 mg. Their psychotic phenomena and behavioural and extrapyramidal symptoms were monitored at 2-weekly intervals. RESULTS: Three out of the eight patients could not tolerate olanzapine even at the lowest available dose. Two patients had clear improvement in psychotic and behavioural symptoms. Three patients were able to tolerate olanzapine but gained only minimal benefit. CONCLUSIONS: Olanzapine at the doses used conferred little advantage over conventional neuroleptics and should only be given with great caution to patients with DLB. The utility of smaller doses deserves further evaluation.

Aged↗
PubMed1998

Changes in the carbon balance of tropical forests: evidence from long-term plots

The role of the world's forests as a "sink" for atmospheric carbon dioxide is the subject of active debate. Long-term monitoring of plots in mature humid tropical forests concentrated in South America revealed that biomass gain by tree growth exceeded losses from tree death in 38 of 50 Neotropical sites. These forest plots have accumulated 0.71 ton, plus or minus 0.34 ton, of carbon per hectare per year in recent decades. The data suggest that Neotropical forests may be a significant carbon sink, reducing the rate of increase in atmospheric carbon dioxide.

Journal Article↗
PubMed1998

What are the relations between Lewy body disease and AD?

Several hospital based autopsy series indicate dementia with Lewy bodies (DLB) to be the second most common pathological subtype of degenerative dementia in elderly subjects. The majority of DLB cases have high densities of beta amyloid senile plaques, whereas neocortical neurofibrillary tangle density is only slightly increased above age-matched normal control values and over tenfold lower than the average in Alzheimer's disease. The interpretation of this Alzheimer type pathology is problematic, reflecting in part changing views about the neuropathological diagnosis of AD itself. AD is characterised by hyperphosphorylation of the microtubular associated protein tau, and DLB by neurofilament abnormalities including phosphorylation, ubiquitination, proteolysis, and cross-linking of constituent proteins. The two diseases appear therefore to be distinct at an ultrastructural and molecular level, a conclusion which is consistent with the fact that the clinical syndromes associated with DLB and AD are sufficiently differentiated to allow for accurate antemortem diagnosis.

Alzheimer Disease↗
PubMed1998

Quantitative and qualitative performance of stroke versus normal elderly on six clock drawing systems.

The utility of the Clock Drawing Test (CDT) in localizing lesions has not been thoroughly examined to date. In the present study, six scoring systems (Freedman et al., 1994; Ishiai, Sugishita, Ichikawa, Gono, & Watabiki, 1993; Mendez, Ala, & Underwood, 1992; Rouleau, Salmon, Butters, Kennedy, & McGuife, 1992; Sunderland et al., 1989; Tuokko, Hadjistavropoulos, Miller, & Beattie, 1992; Watson, Arfken, & Birge, 1993; Wolf-Klein, Silverstone, Levy, & Brod, 1989) were used to assess clock drawings by 76 stroke patients and 71 normal controls. Significant differences were found between normals and stroke patients on all scoring systems for both quantitative and qualitative features of the CDT. Quantitative indices were not helpful in differentiating between various stroke groups (left versus right versus bilateral stroke; cortical versus subcortical stroke; anterior versus posterior stroke). Qualitative features were helpful in lateralizing lesion site and differentiating subcortical from cortical groups. Correlational analyses revealed that CDT performance was related to visuospatial processing and measures commonly used in cognitive screening.

Journal Article↗
PubMed1997

Biomechanical and hydraulic determinants of tree structure in Scots pine: anatomical characteristics.

The development of anatomical, hydraulic and biomechanical properties in Scots pine (Pinus sylvestris L.) stems aged 7 to 59 years was followed. The hydraulic diameter and length of tracheids increased with age to a maximum at 15 and 35 years, respectively. Number of tracheids per unit of sapwood area decreased with age to a minimum of 500-600 tracheids mm(-2). Variations in specific hydraulic conductivity and Young's modulus of stems were associated with variation in anatomical properties. Over the time sequence considered, hydraulic and mechanical properties were positively related to each other and followed a similar developmental pattern, with no suggestion of a trade-off between the two. For most of the tree's life-cycle, heartwood made only a small contribution to whole-section mechanical stiffness because of its location close to the flexural neutral axis, and because of the presence of juvenile wood.

Journal Article↗
PubMed1997

Influence of irradiance on water relations and carbon flux during rooting of Shorea leprosula leafy stem cuttings.

Single-node leafy stem cuttings of Shorea leprosula Miq. were subjected to a high, intermediate or low irradiance treatment for 16 weeks in an enclosed mist propagation system. Before rooting, maximum photosynthesis of the cuttings occurred at an irradiance of 400 micro mol m(-2) s(-1). Although none of the irradiance treatments affected the number of roots produced per cutting, the numbers of cuttings that formed roots were 50 and 30% in the high irradiance (diurnal range of 0-658 micro mol m(-2) s(-1)) and low irradiance (diurnal range of 0-98 micro mol m(-2) s(-1)) treatments, respectively, compared with 62% in the intermediate irradiance treatment (diurnal range of 0-360 micro mol m(-2) s(-1)). Low rooting frequency of cuttings in the high irradiance treatment was associated with water deficits (maximum leaf-to-air vapor pressure deficit (VPD) = 3.6 kPa), whereas cuttings in the low irradiance treatment had a low rooting frequency because they were below the light compensation point most of the time. In the intermediate irradiance treatment, cuttings withstood a daily maximum VPD of 1-2 kPa and recovered overnight from the previous day's deficit, as indicated by higher relative water content (RWC) and stomatal conductance (g(s)) in the morning than in the previous afternoon and evening. Higher RWC and g(s) of cuttings in all treatments on Days 14 and 21 compared with Day 8 probably indicated recovery from water deficit following severance and insertion of the cuttings in rooting medium. There were negative relationships between stem volume of cuttings and both number of cuttings that rooted and number of roots per cutting.

Journal Article↗
PubMed1996

The use of lithium in the treatment of aggressive behaviours with two brain-injured individuals in a state psychiatric hospital.

Brain-injured individuals often experience problems with aggression which can prevent full community reintegration. Two cases involving individuals (one 4 years, one 17 years post-injury) who had been placed in a state psychiatric hospital due to aggressive and/or self-injurious behaviours are discussed. Utilizing medication dosages and behavioural acuity indicators over a 2 year period, the authors demonstrate the efficacy of lithium carbonate in treating aggressive behaviours. Lithium, in concert with other medications, not only led to a decrease in the frequency of aggressive outbursts and in the need for restrictive and costly behaviour control techniques, but also allowed for a significant reduction in the use of neuroleptic medication in one case. The authors conclude that the use of lithium, within the context of an intensive, behavioural rehabilitation programme, may yield positive effects in the control of aggressive behaviour even in long-term post-injury cases.

Adult↗
PubMed1996

Hydraulic conductance, light interception and needle nutrient concentration in Scots pine stands and their relations with net primary productivity.

Aboveground xylem hydraulic conductance was determined in Scots pine (Pinus sylvestris L.) trees and stands from 7 to about 60 years of age. At the stand scale, leaf area index and net primary productivity (NPP, above- plus belowground) increased and reached a plateau at about 25-30 and 15-20 years, respectively; both parameters declined in mature stands. Stand hydraulic conductance followed a similar trend to NPP, with a maximum at about 15-20 years and a pronounced reduction in old stands. At the tree scale, annual biomass growth per unit of leaf area (growth efficiency) declined with tree age, whereas aboveground sapwood volume per unit leaf area, which is linearly related to maintenance respiration costs, steadily increased. Radiation interception per unit leaf area increased significantly with reduced leaf area index of mature stands, despite increased foliage clumping in the canopies of mature trees. Needle nutrient concentration did not change in the chronosequence. Tree hydraulic conductance per unit leaf area was strongly and positively correlated with growth efficiency. We discuss our findings in the context of growth reductions in mature and old trees, and suggest that increased hydraulic resistance and maintenance respiration costs may be the main causes of reduced carbon gain in mature and old trees.

Journal Article↗
PubMed1996

Response of two Afromontane coniferous tree species to light and nutrient supply.

We studied the responses to light and nutrient availability of the two Afromontane conifers Juniperus procera Hochst. ex Endl., reputedly a shade-intolerant species, and Afrocarpus gracilior Polger C.N. Page, a shade-tolerant species. The species behaved similarly in response to light and nutrient availability. Both species showed positive growth rates at photon fluxes of 0.6-0.8 mol m(-2) day(-1). Maximum relative growth rates of 0.15 week(-1) were attained at an irradiance of 8 mol m(-2) day(-1) in the high-nutrient supply treatment. The growth response to high-nutrient supply was achieved by an increase in leaf area ratio rather than by an increase in net assimilation rate. In a 10-week growth experiment, both species displayed an increase in stem extension rate in response to a low red/far-red ratio (0.09) at low irradiance, and A. gracilior also responded by increasing its specific leaf area. Similiar findings were observed in a short-term experiment in which internodes were laterally irradiated.

Journal Article↗
PubMed1996

Long-term impact of clozapine and psychosocial treatment on psychiatric symptoms and cognitive functioning.

OBJECTIVE: The long-term effects of a combination of clozapine and psychosocial treatment were evaluated in a sample of treatment-refractory state hospital patients with schizophrenia. METHODS: A repeated-measure design was used. Thirty-one patients with schizophrenia received both clozapine and an enhanced psychosocial treatment program. Data were collected at baseline and at one-year, two-year, and three-year follow-ups. Psychiatric symptoms, cognitive functioning, dyskinetic movements, and discharge rate were evaluated. RESULTS: Significant reductions in psychiatric symptoms and improvement in cognitive functioning were found. Differences in the pattern of reductions in positive and negative symptoms over the course of the study were noted. The majority of subjects improved sufficiently to be discharged. CONCLUSIONS: Clozapine, when combined with psychosocial treatment, is effective for treatment of patients with schizophrenia who are not responsive to other medications.

Adult↗
PubMed1996

The legal strategies used in operating syringe exchange programs in the United States.

OBJECTIVES: This study sought to identify the strategies used by syringe exchange programs to establish their legality. METHODS: Statutes, court decisions, published studies of exchange programs, and news stories were reviewed, and telephone interviews were conducted with syringe exchange personnel. RESULTS: Twenty-seven exchanges have been authorized by amendments to or judicial interpretations of state drug laws or by administrative action under such laws, or operate in a state that has no laws regulating needles. At least 13 programs operate under claims of legality based on local interpretations of state law, principally public health law. The remaining syringe exchanges operate without a claim of legality. CONCLUSIONS: The deployment of syringe exchanges has been hindered by concerns about their legal status. This study shows that the applicability of drug laws to syringe exchange is open to dispute, and that local public health authorities may under some circumstances rely on their own legal authority to fund or operate syringe exchange programs.

Drug Prescriptions↗