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Biomedical subjects

G Hall

Publications and source records attributed to G Hall.

At least 145 records · Page 8Linked to original sources
PubMed1992

Poor prognosis acute myeloid leukaemia treated by matched unrelated donor marrow transplant without preceding total body irradiation.

Two patients with acute myeloid leukaemia, one in relapse after autologous bone marrow transplantation (BMT) (aged 52 years) and the other with primary resistant disease secondary to previously treated malignancy, have received marrow transplants from matched unrelated donors. Cytoreductive conditioning in both cases was with high-dose combination chemotherapy alone. Engraftment was aided by the administration of total lymphoid irradiation together with in vivo antilymphocyte antibody prior to marrow infusion. Both patients survive in complete remission, currently at 12 and 15 months post-BMT respectively. The avoidance of total body irradiation in BMT patients at high risk of early treatment-related mortality may be advantageous.

Adult↗
PubMed1991

Nuclear scaffolds and scaffold-attachment regions in higher plants.

DNA in the nuclei of eukaryotic organisms undergoes a hierarchy of folding to be packaged into interphase and metaphase chromosomes. The first level of packaging is the 11-nm nucleosome fiber, which is further coiled into a 30-nm fiber. Evidence from fungal and animal systems reveals the existence of higher order packaging consisting of loops of the 30-nm fibers attached to a proteinaceous nuclear scaffold by an interaction between the scaffold and specific DNA sequences called scaffold-attachment regions (SARs). Support for the ubiquitous nature of such higher order packaging of DNA is presented here by our work with plants. We have isolated scaffolds from tobacco nuclei using buffers containing lithium diiodosalicylate to remove histones and then using restriction enzymes to remove the DNA not closely associated with the scaffold. We have used Southern hybridization to show that the DNA remaining bound to the scaffolds after nuclease digestion includes SARs flanking three root-specific tobacco genes. This assay for SARs is termed the endogenous assay because it identifies genomic sequences as SARs by their endogenous association with the scaffold. Another assay, the exogenous assay, depends upon the ability of scaffolds to specifically bind exogenously added DNA fragments containing SARs. The tobacco scaffolds specifically bind a well-characterized yeast SAR, and cloned DNA fragments derived from the 3'-flanking regions of the root-specific genes are confirmed to contain SARs by this exogenous assay.

Journal Article↗
PubMed1991

Chronic postoperative endophthalmitis associated with Actinomyces species.

Actinomyces species, gram-positive, non-spore-forming anaerobic bacilli were isolated from intraocular fluid obtained from four otherwise healthy patients with a delayed onset of postoperative endophthalmitis. One patient had a mixed anaerobic infection with recovery of both Actinomyces israelii and Propionibacterium acnes. In all four patients, early postoperative visual acuity was good but was eventually markedly reduced by intraocular inflammation that was first observed between 21 days and 4 months following uneventful extracapsular cataract extraction and posterior chamber intraocular lens implantation. Inflammation was characterized by anterior segment and vitreous cellular debris in all cases. All eyes responded to therapy that included intraocular, topical, and systemic antibiotics as well as pars plana vitrectomy and partial iridectomy. These cases further illustrate the need for microbiologic investigation, including anaerobic cultures, in all cases of chronic postoperative inflammation following extracapsular cataract extraction, regardless of the time of onset.

Actinomyces↗
PubMed1991

Apicectomy: a comparative clinical study of amalgam and glass ionomer cement as apical sealants.

Healing capacity after apicectomy was investigated in a randomized clinical study of 105 teeth apically sealed with either amalgam or glass ionomer cement. The results were evaluated clinically and radiographically after 1 year. The success rate was high for both materials: 91% for amalgam and 89% for glass ionomer cement. Contamination with moisture and blood adversely affected the outcome for both materials and was significantly more frequent in unsuccessful cases.

Apicoectomy↗
PubMed1991

How common are epileptic seizures in old age?

A large primary-care computerized database was searched to determine the incidence and prevalence of epilepsy and epileptic seizures in old age compared with the general population. The prevalence of subjects with a diagnosis of epileptic seizures was higher in older age groups: 10.9/1000 for sexagenarians, 12.0 for septuagenarians and 13.1 for those over 80, compared with 9.0/1000 in the overall population. The overall prevalence in subjects aged over 60 was 11.8. Annual incidence rose even more sharply in old age: 76/100,000 for sexagenarians, 147 for septuagenarians, and 159 for those over 80, compared with an overall population incidence of 69/100,000. The overall incidence in subjects over 60 was 117. Of incident cases requiring treatment, 35.5% were over 60 years old. Our findings are in keeping with other recent epidemiological studies and in part reflect the age-associated increase in the prevalence of cerebrovascular disease. They have implications for the organization of services for elderly people, for the education of general practitioners and hospital doctors and for directing epilepsy research.

Aged↗
PubMed1991

Acquired equivalence and distinctiveness of cues using a sensory-preconditioning procedure.

In Experiment 1 rats were presented with two flavours, A and B, that were accompanied either by a third common flavour, X, or by two different flavours, X and Y, respectively. An aversion was then established to A, and the extent to which this aversion generalized to B was measured. Stimulus generalization was found to be more marked when A and B had both been presented with the same flavour, X, during pre-exposure than when A and B had been presented with X and Y. In Experiment 2 three target flavours, A, B, and C, were initially presented. In one pre-exposure condition presentations of A and B were accompanied by X, and C was presented alone; in a second condition A and B were presented in isolation, and C was accompanied by X. After an aversion had been established to A, half of the animals in each of the pre-exposure conditions were tested with B, and the remainder were tested with C. In both of the pre-exposure conditions the generalized aversion was more substantial to B than to C. An analysis of these results in terms of the mechanisms that have been supposed to underlie sensory preconditioning is presented.

Animals↗
PubMed1990

Coping profiles associated with psychiatric, physical health, work, and family problems.

Compares the coping profiles of 11 samples (total N = 1,298) of individuals experiencing psychiatric, physical health, work, or family problems. Comparisons are made in individuals with and without anxiety and depression to control for the effects of distress. Coping was similar for samples in similar problem categories but different for samples in different categories. Psychiatric patients made more use of avoidance and less use of social supports than individuals in the other categories. Samples with physical health problems were among the most frequent users of social supports. Individuals with a family problem were among the most frequent users of problem-focused coping and the least frequent users of self-blame. Groups with work stress were the most frequent users of self-blame. These results suggest that coping profiles may be useful in describing and differentiating groups of stressed individuals.

Adaptation, Psychological↗
PubMed1990

Detection and quantitation by lysis-filtration of bacteremia after different oral surgical procedures.

Patients with bacteremia after dental extraction, third-molar surgery, dental scaling, endodontic treatment, and bilateral tonsillectomy were studied by means of lysis-filtration of blood samples with subsequent aerobic and anaerobic incubation. Samples were obtained before, during, and 10 min after treatment. Bacteremia was observed in 100% of patients after dental extraction, 55% of patients after third-molar surgery, 70% of patients after dental scaling, 20% of patients after endodontic treatment, and 55% of patients after bilateral tonsillectomy. Anaerobic microorganisms were isolated more frequently than aerobic microorganisms were, and viridans group streptococci were the most commonly isolated bacteria. Ten minutes after treatment, the frequency as well as the magnitude of bacteremia showed pronounced reduction.

Adolescent↗
PubMed1990

Farmer's lung in Northern Ireland.

A total of 381 farmers in Northern Ireland were studied using a questionnaire, pulmonary function tests, and antibody levels to Micropolyspora faena to assess the incidence of farmer's lung. Twenty (4.9%) had a history of a previous diagnosis of farmer's lung by their doctor. Forty four (10.4%) had delayed onset symptoms compatible with farmer's lung, 32 (7.9%) had precipitant antibody, and 61 (15%) had raised antibody by the enzyme linked immunosorbent (ELISA) method. Restricted lungs were present physiologically in 40 (9.8%). A confirmation of delayed symptoms and precipitant antibody was present in seven (1.7%) whereas delayed symptoms and ELISA antibody was present in nine (2.2%). Using either antibody method only two (0.5%) had a combination of antibody to M faenae, delayed onset symptoms, and restricted pulmonary physiology.

Antibodies, Bacterial↗
PubMed1990

Context-specific conditioning in the conditioned-emotional-response procedure.

In 3 experiments, rats were used to investigate the conditions that influence the transfer of a conditioned emotional response from 1 context to another. The subjects experienced training in 2 contexts on each day. In Experiment 1, subjects received a single conditioning trial with a different target stimulus in each of the 2 contexts. Conditioned responding was found to be more vigorous when the target was presented subsequently in the context in which conditioning had taken place than when it was presented in the other context. Experiments 2 and 3 confirmed these results and also showed that neither the unconditioned response evoked by the target stimulus nor the conditioned response acquired after multiple training trials showed evidence of context specificity. Possible reasons for the difference in outcome between single-trial and multitrial conditioning procedures are discussed.

Animals↗