Search PubMed⌕ Search

Biomedical subjects

R D Hill

Publications and source records attributed to R D Hill.

At least 37 records · Page 2Linked to original sources
PubMed1995

The relationship between the mini-mental state examination and cognitive functioning in normal elderly adults: a componential analysis.

The relationship between the Mini-Mental State Examination (MMSE) and selected cognitive performance indices was examined in a sample of 251 non-demented adults over 75 years of age. MMSE items were divided into I 1 binomial content domains and an examination of these revealed that only seven had sufficient variability to predict cognitive performance. A factor analysis with these items yielded three factors, reflecting memory, spatial skill, and the ability to follow commands. After controlling for age and education, these factor scores were included as predictors of specific cognitive tasks including two measures of free recall, and two measures of visuospatial skill. The memory factor score was a strong predictor of the two free recall tasks and block design. The spatial factor score contributed to the prediction of the two visuospatial measures, as well as free recall of organizable words. The results suggest that, in normal ageing, the predictive value of the MMSE is due to subset of cognitively demanding items that are heavily influenced by both memory and visuospatial skills.

Aged↗
PubMed1995

Episodic memory and visuospatial ability in detecting and staging dementia in a community-based sample of very old adults.

BACKGROUND: This study examined the efficacy of a cognitive test battery in detecting and staging dementia in a community-based sample of very old adults. METHOD: The sample consisted of 398 nondemented and 108 demented adults taken from all the inhabitants in the Kungsholmen parish of Stockholm, Sweden (2,368 individuals), aged 75 years and older, who were part of a large-scale epidemiological study on aging and dementia. Participants received a cognitive test battery that consisted of specialized episodic memory tasks, as well as standardized psychometric measures of visuospatial ability and primary memory. RESULTS: A discriminant analysis revealed that highly supported episodic memory tasks (recognition, cued recall) were primarily responsible for correctly classifying normal old adults (94.5%) from those with the diagnosis of dementia (66.7%). Using the Mini-Mental State Exam (MMSE) as the criterion of dementia severity, a correct classification of 88.9% was achieved for mildly demented subjects and 77.8% for moderately demented subjects. Visuospatial tasks made the greatest contribution in distinguishing those at different levels of dementia severity. CONCLUSION: The results of this investigation indicate that cognitively supported measures assessing episodic memory may be particularly useful in the detection of dementia, whereas visuospatial measures are more effective in staging the disease. Consistent with biological models of the progression of dementia, this suggests that visuospatial abilities may deteriorate later and/or at a slower rate than episodic memory skills in the early stages of dementia. It is noteworthy that these conclusions are based on samples of very old adults taken from the general population.

Aged↗
PubMed1995

The role of demographic and life style variables in utilizing cognitive support for episodic remembering among very old adults.

This research investigated the influence of individual difference variables within demographic and life-style domains on episodic recall tasks in which the level of cognitive support increased incrementally. The community-based sample consisted of 253 healthy older adults taken from the Kungsholmen parish in Stockholm, Sweden. Utilizing hierarchical regression procedures, two questions were addressed with regard to the selected individual difference variables: (a) the degree to which they could predict episodic recall and (b) whether they differentially influenced the magnitude of performance gains from the provision of cognitive support in the form of study time, item organizability, and retrieval cues. The results showed that age was negatively related to performance, whereas education and participation in social activities exerted a positive influence on performance. Exercise was also positively related to performance, but only in the least supported tasks. With regard to utilization of cognitive support, education was positively related to performance benefits from more study time and item organizability, age was negatively related to the effect of item organizability, and social activity was positively associated with the ability to benefit from retrieval cues. These results highlight the role of individual difference measures in episodic memory functioning in late adulthood and indicate that these variables are important in predicting the extent to which older adults are able to utilize cognitive support to enhance episodic recall.

Adaptation, Psychological↗
PubMed1995

Video Respite: an innovative resource for family, professional caregivers, and persons with dementia.

The development of a new and promising resource for family, professional caregivers, and persons with dementia is detailed in this article. The concept, Video Respite, refers to the initial goal of creating videotapes specifically for persons with dementia to capture and maintain their attention, enabling caregivers to have respite time. Ten 20-53-minute videotapes are described along with their potential benefits and limitations. Early research findings reveal that most persons with Alzheimer's disease (AD) watch and participate with the tapes, caregivers use the time for respite, and staff of SCU's report the tapes to be calming for the residents.

Aged↗
PubMed1995

Pollen allergen homologues in barley and other crop species.

Pollen from 10 agricultural plant species was surveyed for the presence of proteins crossreactive with group I, group IV and group IX allergens. Barley (Hordeum vulgare), maize (Zea mays), rye (Secale cerale), triticale (xTriticosecale cereale), oats (Avena sativa), Canola (Brassica napus) and sunflower (Helianthus annus) pollens contained numerous allergen cognate proteins. Northern blot analysis of barley pollen RNA revealed the presence of group I and group IX allergen transcripts. The barley pollen cDNA hvp9742, and three other cloned allergens: phlenum protense (Phl p) V, Phl p Va and Lolium perenne (Lol p) 1b, were demonstrated to have extensive nucleotide and amino acid sequence similarity to the Poa p IX isoallergens. It was concluded that hvp9742 represents a Poa p IX isoallergen homologue expressed by barley pollen, and was therefore designated Hor v IX. It is further shown that the most highly conserved domains of all seven proteins, including Hor v IX, map to previously defined Poa p IX antibody binding epitopes.

Allergens↗
PubMed1995

An optical practice based diabetic eye screening programme.

In many cases, blindness due to diabetic retinopathy can be prevented provided treatment with laser photocoagulation is used at the correct time. A screening programme is required to identify cases of sight threatening retinopathy. An optical practice based diabetic eye screening programme has been established in Dorset. The optometrist undertaking the examination is paid a fee. The findings are recorded on a coded form and sent to the hospital diabetologist who recalls positive cases. Seventy-six optical practices have joined the scheme and 3224 patients have been screened in the first 6 months (Dorset population 655,000). In the Poole area (population 230,000), 1922 patients were screened and 129 (6.7%) were recalled in 6 months. Outcome of 3 months screening, identified 59 recalls. Referral to the opthalmologist was made in 15 cases for potentially sight threatening retinopathy, 14 cases were followed in the diabetic clinic for significant background retinopathy, and 24 cases were returned to the annual screening in the optical practices. Six cases where the patients either failed or were unable to attend were reviewed by the GP. An optical practice based diabetic eye screening programme has been successful in screening a large number of patients.

Diabetic Retinopathy↗
PubMed1995

Determinants of functional abilities in dementia.

OBJECTIVES: To determine the extent to which selected variables within demographic, psychometric, and memory domains can predict functional abilities in dementia. DESIGN: Hierarchical regression analyses were employed to predict functional abilities, while controlling for disease severity, using the Mini-Mental State Exam (MMSE). SETTING AND PARTICIPANTS: A total of 2368 inhabitants of Kungsholmen parish in Stockholm, Sweden, aged 75 years of age or older. Eighty-one subjects with confirmed dementia (MMSE, M = 17.9; SD = 5.26) were selected from the study population. The mean age was 84.5 years (SD = 5.58), and 72% were female. MEASUREMENTS: Participants received a battery of standardized neuropsychological instruments and selected experimental tasks that measured visuospatial ability as well as primary and episodic memory. Self-care was assessed using the Katz index of activities of daily living (ADL); instrumental activities of daily living (IADL) were assessed through the primary caregiver, who responded to questions related to functional competence of the participant. RESULTS: Hierarchical regression procedures revealed that disease severity was the strongest predictor of ADL and IADL performance. Controlling for disease severity, a measure of visuoperception (Poppelreuter's figures) also made a significant contribution to the explanatory variance in both ADL and IADL function. Beyond disease severity and visuoperception, years of schooling and disease duration were marginally predictive of IADL performance. CONCLUSION: It is possible to predict functional abilities in dementia on the basis of individual difference variables. Multiple variables were initially correlated with ADL and IADL performance; however, after controlling for disease severity, visuoperception was the only predictor of ADL scores. In addition to visuoperception, IADL scores were also marginally predicted by education and disease duration. These findings highlight the importance of peripheral sensory processes in adaptive function in dementia. They also suggest that although many variables may be correlated with functional ability, their explanatory role, particularly with regard to self-care skills, is diminished in the presence of the disease.

Activities of Daily Living↗
PubMed1994

A cereal haemoglobin gene is expressed in seed and root tissues under anaerobic conditions.

Legumes, and a very few non-legume plant species, are known to possess functioning haemoglobin genes. We describe here the characterization of a haemoglobin cDNA isolated from barley. The deduced amino acid sequence shows 71% amino acid identity with a non-legume haemoglobin gene, a further 16% of the residues being conservative replacements. The barley cDNA also hybridizes to genomic sequences in rye, maize and wheat. The demonstration of a gene from a monocotyledon with close sequence homology to the known non-legume plant haemoglobins fills a major gap in the known distribution of haemoglobin genes in the plant kingdom. The expression of the gene is induced in isolated barley aleurone layers exposed to anaerobic conditions, and the roots of flooding-stressed barley plants. The expression of the RNA under anoxic conditions is similar to that of a known anaerobic response gene, alcohol dehydrogenase. Our results suggest that the increased expression of haemoglobin RNA is an integral part of the normal anaerobic response in barley. The findings are discussed in the light of current theories of haemoglobin function and evolution.

Alcohol Dehydrogenase↗
PubMed1994

Prostaglandin E1 does not accelerate rTPA-induced thrombolysis in acute myocardial infarction.

Fifteen patients who arrived between 6 and 24 hours after the onset of acute myocardial infarction and who were found to have totally occluded coronary arteries, received aspirin, heparin, and tissue plasminogen activator given over 3 hours. Eight patients were randomly assigned to receive intravenous prostaglandin E1, 20 ng/kg/min for 6 hours, while seven patients received placebo infusion. Coronary arteriography begun immediately before the start of tissue plasminogen activator and repeated every 15 minutes revealed restoration of antegrade flow in two of eight (25%) patients treated with prostaglandin E1 and in two of seven (28%) patients receiving placebo. Pharmacologic sampling of tissue plasminogen activator levels were performed at baseline and 30, 45, 60, 75, 90, 135, 180, 190, 210, and 240 minutes afterwards for assessment of tissue plasminogen activator antigen. There was no difference in fibrinogen levels and no difference in tissue plasminogen activator antigen levels at these time periods. Clearance values of tissue plasminogen activator were calculated and were not different between the two groups. These data do not support the use of prostaglandin E1 for the acceleration of reperfusion in patients receiving tissue plasminogen activator for acute myocardial infarction.

Alprostadil↗
PubMed1994

Predicting episodic memory performance in dementia: is severity all there is?

Whether individual differences in demographic, psychometric, and biological domains can predict episodic memory in dementia was investigated. Mildly to moderately demented very old persons performed episodic memory tasks (free recall and recognition of slowly and rapidly presented random words, free and cued recall of organizable words, and recognition of dated and contemporary famous faces). A factor analysis of the memory measures yielded 2 factors, 1 indexing recall and 1 recognition. Controlling for severity of dementia, only 2 predictors contributed to performance: (a) Block Design (a marker of fluid intelligence) was positively related to recall, and (b) age was negatively related to recognition. Although these results are similar to data reported on predictors of episodic memory in normal aging, (a) the number of predictive variables appears to be reduced in dementia, and (b) age seems to affect recall and recognition differentially in normal aging and dementia.

Activities of Daily Living↗
PubMed1994

Mortality in diabetic subjects: an eleven-year follow-up of a community-based population.

In 1979, all the known diabetic subjects (849) were identified from a community (population 81851), of whom 717 (85%) were reviewed by a single observer. Using the NHS Central Register, follow-up was completed for 98% of subjects. After 11 years, 306 (42.7%) diabetic subjects had died, of whom 65 were insulin treated and 241 were non-insulin treated. Circulatory disease accounted for 168 (54.9%) deaths, of which 124 (73.8%) were due to ischaemic heart disease. The standardized mortality ratio (SMR) for all causes of death, based on data from England and Wales, was significantly raised for both insulin-treated and non-insulin-treated patients (1.75, 95% CI 1.35 to 2.24 and 1.32, 95% CI 1.15 to 1.50, respectively). SMRs for all cause mortality were significantly greater for diabetic subjects in the 45-64 (SMR, 1.97, 95% CI 1.34 to 2.80), 65-74 (SMR 1.59, 95% CI 1.27 to 1.97 and 75 years and over (SMR 1.26, 95% CI 1.08 to 1.45) age ranges. Using a proportional hazards model, after adjusting for age and gender, systolic blood pressure and vibration threshold were significant predictors of all cause mortality in insulin-treated subjects. For non-insulin-treated subjects, blood glucose, systolic blood pressure, glycated haemoglobin, retinopathy, proteinuria, coronary artery disease, and stroke were significant baseline predictors of mortality. No association was found for serum cholesterol, body mass index, diastolic pressure or cigarette smoking in either treatment group.

Adolescent↗
PubMed1993

The impact of long-term exercise training on psychological function in older adults.

The effect of long-term aerobic training on psychological function was examined in 87 sedentary older adults who engaged in a year-long endurance exercise training program compared with a nonexercising control group. In addition to improved cardiovascular fitness, a positive change in self-reported morale was found for the exercise condition. Of the cognitive functions measured, a significant effect was noted for the Wechsler Memory Scale (WMS) Logical Memory subtest; however, this effect was caused by a decline in performance from pre- to posttesting in the control group. Long-term exercise training had little, if any, effect on improving cognitive function in this older adult sample.

Affect↗
PubMed1993

Self-generated mnemonics for number recall in young and old adults.

Self-generated strategies for recall of number facts were examined in 164 adults who ranged in age from 20 to 86 years. Participants recalled a number list that included six 2-digit prices and six 4-digit phone numbers. Following recall, participants reported their encoding strategies. A larger percentage of the younger subjects (< 49 yr.) reported using a specific verbal mediator to facilitate encoding, and younger subjects recalled more 2-digit and 4-digit numbers. Across age groups, the self-reported use of encoding strategies facilitated recall.

Adult↗
PubMed1992

Characterization of a gene family encoding abscisic acid- and environmental stress-inducible proteins of alfalfa.

The phytohormone abscisic acid (ABA) has been proposed as a common mediator controlling adaptive plant responses to a variety of environmental stresses, including water deficit, salinity, wounding, and low temperature. We have recently isolated three cDNAs, pUM90-1, pUM90-2, and pUM91-4, from a cDNA library of ABA-induced mRNAs of alfalfa. These cDNA clones exhibit a very high degree of sequence homology with one another and sequence similarities with certain regions of several stress- and ABA-inducible genes. The polypeptides encoded by these cDNAs are very rich in glycine (35-40%), histidine (7-15%), asparagine (8-14%), and tyrosine (5-10%) and have no tryptophan and proline. All of the encoded polypeptides contain characteristic tandem repeats comprising glycine residues intercepted with histidine and/or tyrosine. The RNAs corresponding to a representative cDNA, pUM90-1, were induced after treatment of seedlings with low temperature, drought, salt, and wounding stress, but not by heat; the induction was maximal under low temperature treatment. ABA and ABA analog rapidly induced the expression of these genes, whereas gibberellic acid treatment exhibited no induction whatsoever. These genes appear to be specifically induced in the shoot tissues. Analysis of ABA induction of genes corresponding to pUM90-1 in alfalfa seedlings of different age groups demonstrated that these genes were inducible in seedlings/plants of all age groups examined. Taken together these results suggest that these cDNA clones encode a group of proteins that are inducible by ABA and multiple environmental stresses and correspond to a new family of genes of plants, designated as ABA- and environmental stress-inducible genes.

Abscisic Acid↗
PubMed1992

Psychometric discrimination of moderate senile dementia of the Alzheimer type.

A brief psychometric battery was used to differentiate a sample of 56 individuals classified as having mild senile dementia of the Alzheimer type (SDAT) from 38 individuals with moderate SDAT. Using discriminant analysis techniques, a modest differentiation was obtained. It was noted that specific ability domains, namely, short-term recognition memory, visuospatial reasoning, and verbal ability, contributed to the discriminant function. Although the same domains have been found to differentiate SDAT at earlier stages, individual tests varied in the current sample as a function of marked decrements in ability levels at this advanced stage of the disease. The results suggest that the effectiveness of specific psychometrics for differentiating individuals with SDAT may vary as a function of relative disease stage.

Aged↗
PubMed1992

An efficient lightning energy source on the early Earth.

Miller and Urey suggested in 1959 that lightning and corona on the early Earth could have been the most favorable sources of prebiotic synthesis. In 1991 Chyba and Sagan reviewed the presently prevailing data on electrical discharges on Earth and they raised questions as to whether the electrical sources of prebiotic synthesis were as favorable as was claimed. The proposal of the present paper is that localized lightning sources associated with Archaean volcanoes could have possessed considerable advantages for prebiotic synthesis over the previously suggested global sources.

Earth, Planet↗
PubMed1992

Mapping of antibody binding epitopes of a recombinant Poa p IX allergen.

Antibody binding epitopes of a recombinant Poa p IX allergen were delineated using recombinant DNA and solid-phase peptide synthesis procedures. The full-length cDNA clone KBG60 and its four overlapping recombinant fragments, KBG60.1, KBG60.2, KBG8.3 and KBG10 which spanned the entire molecule were synthesized in E. coli with aid of the plasmid expression vector, pWR590.1. The antigenic and allergenic sites of these recombinant proteins were analyzed by ELISA using human IgE and murine IgG antibodies. It was thus demonstrated that although the epitopes were found on all the fragments tested, the majority of these were located on a C-terminal fragment, rKBG8.3. Furthermore, synthetic peptides were also employed to identify the epitopes of rKBG60 protein. The use of antisera raised against native KBG pollen extract and the recombinant KBG8.3 protein to scan a total of 56 overlapping deca-penta peptides, covering the entire rKBG60 protein, revealed that 10 positive peptides involved in the antibody-binding site(s). Taken together, the results of these studies indicate that rKBG60 protein possesses at least 10 antibody binding epitopes.

Allergens↗