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Biomedical subjects

L Atkinson

Publications and source records attributed to L Atkinson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Stalk cell formation in monolayers from isolated prestalk and prespore cells of Dictyostelium discoideum: evidence for two populations of prestalk cells.

Cells from the pseudoplasmodial stage of Dictyostelium discoideum differentiation were dispersed and separated on Percoll gradients into prestalk and prespore cells. The requirements for stalk cell formation in low-density monolayers from the two cell types were determined. The isolated prespore cells required both the Differentiation Inducing Factor (DIF) and cyclic AMP for stalk cell formation. In contrast, only part of the isolated prestalk cell population required both cyclic AMP and DIF, the remainder requiring DIF alone, suggesting the possibility that there were two populations of prestalk cells, one independent of cyclic AMP and one dependent on cyclic AMP for stalk cell formation. The finding that part of the prestalk cell population required only a brief incubation in the presence of DIF to induce stalk cell formation, whilst the remainder required a considerably longer incubation in the presence of both DIF and cyclic AMP was consistent with this idea. In addition, stalk cell formation from cyclic-AMP-dependent prestalk cells was relatively more sensitive to caffeine inhibition than stalk cell formation from cyclic-AMP-independent prestalk cells. The latter cells were enriched in the most anterior portion of the migrating pseudoplasmodium, indicating that there is spatial segregation of the two prestalk cell populations. The conversion of prespore cells to stalk cells took longer and was more sensitive to caffeine when compared to stalk cell formation from cyclic-AMP-dependent prestalk cells.

Caffeine↗
PubMed1988

Low IQ samples and WAIS-R factor structure.

Wechsler Adult Intelligence Scale-Revised subtests, as administered to 204 individuals with low IQs, were factor analyzed. Solutions proved comparable to structures extracted from the normative data and to solutions based on WAIS, WISC-R, and WISC data for persons with low IQs. Given the restricted IQ range and diminished variance involved, this study provides a particularly stringent test of WAIS-R factor structure. Subtest contributions to general intelligence, however, tend to be more similar among samples of persons with low IQs than between the present low IQ sample and the standardization sample. Clinicians working with intellectually low functioning clients can validly make factor-based test interpretations, but use of short-forms may be dangerous.

Adult↗
PubMed1988

Head injury.

Explore the source record for details and available documents.

Accidents, Traffic↗
PubMed1987

Genome structure in Streptomyces spp.: adjacent genes on the S. coelicolor A3(2) linkage map have cotransducible analogs in S. venezuelae.

Cotransduction analysis in Streptomyces venezuelae with the generalized transducing phage SV1 showed that several pairs of likely analogs of markers that are adjacent on the conjugational linkage map of Streptomyces coelicolor A3(2) were cotransducible and therefore physically close together. This supports the contention that taxonomically distinct "species" of Streptomyces are genetically closely related.

Chromosome Mapping↗
PubMed1986

A replicated cluster solution in a heterogeneous psychiatric population.

Two cluster analytic studies were conducted to explore groupings of patients in a heterogeneous psychiatric population. Study 1 (N = 170) provided support for the derivation by a cluster analytic method of five meaningful clinical groups of patients. Based on an extensively modified inventory and a different population of psychiatric patients, results from Study 2 (N = 224) provided further indication of the stability of the clusters. It was concluded that cluster analysis may provide a viable method as a classification system for a heterogeneous population of psychiatric inpatients.

Adolescent↗
PubMed1986

Relation between alcohol intake, myocardial enzyme activity, and myocardial function in dilated cardiomyopathy. Evidence for the concept of alcohol induced heart muscle disease.

Detailed drinking histories were taken in 38 patients in whom dilated cardiomyopathy was diagnosed by cardiac catheterisation and left ventricular biopsy. On the basis of the drinking history twenty patients were classified as being in an abstinent or light drinking group and eighteen patients as being in a heavy drinking group (daily alcohol intake in excess of 80 g or cumulative lifetime intake exceeding 250 kg). Activities of myocardial creatine kinase, lactate dehydrogenase, alpha hydroxybutyric dehydrogenase, malic dehydrogenase, and aspartate amino-transferase were all higher in the heavy drinkers and myocardial enzyme activity correlated with cumulative lifetime alcohol intake, maximum daily intake, and recent daily intake. Activities of creatine kinase, alpha hydroxybutyric dehydrogenase, and malic dehydrogenase correlated with ejection fraction, irrespective of the alcohol intake of the patient. These findings were not altered by exclusion of patients with hypertension. The results indicate that among patients with dilated cardiomyopathy there is a group characterised by a high alcohol intake and raised myocardial tissue enzymes which supports the concept of alcoholic heart muscle disease as a distinct entity.

Adult↗
PubMed1985

Cavernous haemangioma of the orbit.

Cavernous haemangioma is considered the most common primary orbital tumour. We present three cases of cavernous haemangioma of the orbit presenting with deterioration of vision and painless unilateral exophthalmos. A review of the current literature available is compared with our findings. The diagnostic examinations that are most helpful in deciding that an orbital cavernous haemangioma is present include plain film X-ray examination of the orbits and sinuses, B-mode ultrasonography and computerized axial tomography. Each patient underwent a transcranial surgical procedure for removal of the tumour, after pre-operative evaluation.

Adult↗
PubMed1985

School refusal: the heterogeneity of a concept.

Finer discrimination among school refusers may help clear the confusion surrounding the school refusal syndrome. This paper reviews two aspects of the literature-that dealing with etiological theories and that which explicitly addresses the heterogeneity of the school refusal concept. Variables that consistently emerge as potential discriminators among school refusers are identified, and an attempt is made to determine their interrelationships.

Achievement↗
PubMed1979

Craniofacial surgery.

The historical development of craniofacial surgery for congenital abnormality is reviewed. The work of a second Australian unit of craniofacial surgery which has been formed in Brisbane is described, current indications for surgery are defined, and the preoperative preparation is outlined. The treatment of six children with hypertelorism, Crouxon's disease, Apert's syndrome, and bicoronal craniostenosis is described and the postoperative results and complications are outlined. There is a case for early surgery.

Child↗
PubMed1978

Melanoma of the central nervous system.

The neurological manifestations of melanoma are analysed in this review of 1,500 patients in the Queensland Melanoma Project from 1963 to 1969. Three hundred and fifty patients have died, and 113 were recognized as having central nervous system metastases. The natural history of these metastases was examined, together with the results of a limited number of autopsies. The results of treatment are discussed.

Adult↗
PubMed1978

Diagnosis of coronary artery disease by estimation of coronary sinus lactate.

In an attempt to assess the value of coronary sinus lactate estimation before and during atrial pacing for the diagnosis of obstructive coronary artery disease, 70 patients with angina were investigated in this way and by selective coronary arteriography. Thirty-five had radiologically normal coronary arteries and 35 had coronary artery disease. When the change in coronary arteriovenous lactate difference was less than 0.09 mmol/l (0.8 mg/100 ml) between the control and the peak atrial pacing sample, the coronary arteries were normal except in one patient who had distal disease of a single vessel. When the change was greater than 0.22 mmol/l (2.0 mg/100 ml) coronary artery disease was always found, and when the change was greater than 0.39 mmol/l (3.5 mg/100 ml) there was always disease of two or three vessels. Unfortunately, the presence or absence of coronary artery disease could not be predicted when the change fell between 0.09 and 0.22 mmol/l (0.8 and 2.0 mg/100 ml). Estimation of coronary sinus lactate before and during atrial pacing can thus frequently distinguish patients with normal coronary arteries from those with coronary artery disease.

Adult↗
PubMed1978

An investigation into the ability of elderly patients continuing to take prescribed drugs after discharge from hospital and recommendations concerning improving the situation.

An investigation was made by an Occupational Therapist into the problems encountered by 50 elderly patients in the self-administration of drugs prior to discharge home. The questions asked the patients are enumerated and recommendations are made concerning how improvements can take place so that many more of the elderly will take the prescribed drugs in the right doses at the right time on discharge home.

Aged↗