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Biomedical subjects

J A Adams

Publications and source records attributed to J A Adams.

At least 109 records · Page 6Linked to original sources
PubMed1988

Primary polycythaemia, essential thrombocythaemia and myelofibrosis--three facets of a single disease process?

Primary polycythaemia (PP), idiopathic myelofibrosis (MF), essential thrombocythaemia (ET) and chronic granulocytic or myeloid leukaemia (CGL) are clonal disorders of the pluripotent haemopoietic stem cells. We have studied granulocyte, megakaryocyte and erythroid progenitors from the peripheral blood of 7 patients with PP, 9 with ET, 19 with MF and 6 with CGL in order to characterise similarities and differences at the committed progenitor cell level. Spontaneous megakaryocytic and erythrocytic growth was characteristic of MF, PP and ET but was not seen in CGL. Circulating erythroid (BFU-E) and granulocyte/macrophage (CFU-GM) progenitors were markedly increased in MF and CGL, less raised in ET and closest to normal in PP. Erythropoietin-independent erythroid bursts (EIBFU-E) grew from the blood of patients with MF, PP and ET but spontaneous growth of megakaryocytes occurred in only MF and ET. These results suggest a progression of increasing abnormality from PP, where EIBFU-E occurred with relatively normal numbers of circulating progenitors, to ET where both EIBFU-E and megakaryocyte precursors regularly occur with elevated numbers of progenitors, to MF where spontaneous BFU-E, CFU-Mk and CFU-GM occur at high levels.

Colony-Forming Units Assay↗
PubMed1986

Self-esteem and perceived stress in young adolescents with chronic disease. Unexpected findings.

This pilot study was designed to investigate the relationship between perceived stress, self-esteem and "functional" pain in young adolescents with and without chronic disease. Twenty children with chronic disease and 15 without who were seen in a pediatric outpatient clinic completed a symptom survey, the Piers-Harris Self-Concept Survey, and Lewis's Feel-Bad Scale. Adolescents with significant self-reported complaints of abdominal pain, chest pain, and headaches (without documented organic cause) scored higher on the Feel-Bad scale (p less than 0.002) and lower on the self-concept scale (p less than 0.02) than those without functional complaints. Patients with chronic disease scored higher on the self-esteem measure (61 +/- 14 versus 48 +/- 14, p less than 0.01) and lower on the stress measure (80 +/- 40 versus 120 +/- 54, p less than 0.02) than those without a chronic disease. These findings of lower stress and higher self-esteem in adolescents with chronic illness were unexpected. Possible explanations are discussed.

Adolescent↗
PubMed1985

Incidence of hyperbilirubinemia in breast- vs. formula-fed infants.

A retrospective study of 233 consecutively born full-term infants was performed to determine the effect of several variables on the development of hyperbilirubinemia. Thirty-five (15%) of the infants developed peak bilirubin levels greater than 12 mg/dl in the first week of life. Step-wise multiple regression analysis revealed that breast-feeding was the most predictive of a group of eight variables for the development of hyperbilirubinemia greater than 12 mg/dl. The correlation between type of feeding and hyperbilirubinemia was significant (p less than 0.02). None of the other factors evaluated was significantly associated with hyperbilirubinemia. Breast-fed infants also were found to have a significantly higher incidence of hyperbilirubinemia greater than 15 mg/dl; 12 of 101 (12%) infants compared with 2 of 117 (2%) formula-fed infants (p less than 0.002). This group of infants accounted for the increased incidence of hyperbilirubinemia greater than 12 mg/dl in breast-fed infants. There was no significant correlation between weight loss and development of hyperbilirubinemia in the breast-fed infants.

Birth Weight↗
PubMed1982

Haematopoietic stimulators in the serum of patients with severe aplastic anaemia.

Recent studies on sera from patients with aplastic anaemia show it to contain both stimulators and inhibitors of granulopoiesis. We have examined the serum of patients with aplastic anaemia in a short-term liquid culture system of human bone marrow which permits CFU-C proliferation. Increases in CFU-GM numbers over control values were observed with aplasia sera. All sera produced increased megakaryopoiesis, but no alteration in growth of the fibroblasts and macrophages of the adherent stromal layer. With one exception the sera had no significant direct colony stimulating activity when assayed in agar culture, but increased colony numbers were observed when the sera was incorporated into a sub-optimal feeder layer of peripheral blood leucocytes. When aplastic serum was added to adherent cell-depleted liquid cultures, the CFU-C stimulating property was lost, but increased megakaryopoiesis still occurred. These results indicate the presence of a direct-acting thrombopoietin and an indirect-acting stimulator of CFU-C proliferation in the serum of patients with aplastic anaemia, which may be related to the pathophysiology of the condition.

Adolescent↗
PubMed1981

Do cognitive factors in motor performance become nonfunctional with practice?

Cognitive factors in motor behavior were defined as verbal and imagery mediators for a discrete, sequential motor task. The question was asked whether these mediators become nonfunctional with extended practice. Non-motor interference training was given in inappropriate verbal and imagery mediation. If cognitive factors in the motor task involve verbal an/or imagery dimensions, and they dominate early in learning, then the non motor interference training should produce relatively large negative transfer effects in the motor performance early in learning and little or no such effects late in learning. The results did not conform to expectation; small negative transfer effects were found both early and late in learning. The discussion considered several possible reason for the outcome: the motor task was dominated by visual and proprioception factors rather than cognitive ones, the method of delivering knowledge of results may have minimized cognitive factors, or the hypothesis is wrong.

Journal Article↗
PubMed1979

Reader preference for report typefaces.

A postal survey of typeface preference is described. The survey was designed to help in the choice of typeface to be used for the internal technical Reports produced by the Post Office Research Department. Type setting for these Reports is carried out using an IBM Selectric Composer for which seven typefaces suitable for reports are available. One hundred and twenty-five people who regularly receive copies of these Reports and 57 Trainee Technicians (Apprentices) were asked to arrange these seven typefaces in order of preference and record this ranking on a response sheet. About 85% of both groups returned response sheets for statistical analysis. The results showed a significant preference for three of the typefaces: Press Roman, Theme and Univers. Of these, Press Roman is used for the text of Research Department Reports and Univers is used on diagrams and tables.

Journal Article↗
PubMed1978

Bacterial utilization of cyclo(glycl-L-prolyl).

3 strains of soil bacteria (2 Achromobacter, 1 Flavobacterium) were isolated by growth on cyclo(Gly-L-Pro) as carbon/nitrogen source. Good growth required yeast extract supplements. Utilization of cyclo(Gly-L-Pro) was inducible. Many efforts failed to obtain active cell-free preparations. Injected radioactive cyclo(Gly-L-Pro) was excreted intact by the albino rat; in contrast, injected radioactive H-Gly-L-Pro-OH was extensively metabolized.

Dipeptides↗
PubMed1976

Exposure in the post-operative management of surgical wounds. Report of a trial.

The ancient method of leaving operative wounds completely exposed to the air throughout the healing period is assessed on the basis of a trial in 100 surgical wounds (excluding traumatic wounds and wounds of the hand and knee). The method offers two chief advantages; the wound can be regularly and easily inspected, and any collection of secretions which can lead to skin complications and superficial sepsis can be dealt with. The results are analysed and compared favourably with those of conventional dressing techniques.

Adolescent↗
PubMed1975

Morphogenetic gradients in moltiple-graft Hydra viridis. I. The effects of colcemid and colchicine.

The morphogenesis of so-called secondary (2 degree) heads, budding regions and feet, and separations at graft borders, is studied in multiple-graft animals containing three gastric regions (3g animals) treated with Colcemid or colchicine. Control animals consist of three non-treated pieces. Animals consisting of two non-treated and one treated piece are also employed. The main effects of Colcemid are the promotion of graft healing at the distal graft border, and of 2 degree head formation on the proximal gastric region (g-1). Colchicine also promotes graft healing at the distal graft border, but in contrast to the effect of Colcemid, promotes the formation of ectopic feet (tertiary feet) and inhibits head regeneration at the distal end of the middle gastric region (g-2). Colchicine also accelerates an inversion of polarity in 2 degree budding regions on the g-2 pieces of animals with 2 degree heads on their g-1 pieces. Treatment of a distal graft piece with Colcemid promotes 2 degree head formation on the nearest proximal piece which is not treated, but the inhibition of 2 degree head formation by colchicine occurs only on colchicine treated pieces. The morphogenetic effects of the drugs are interpreted as consequences of their actions on nerve differentiation and cell division. The paper argues that homeostatic control of a hydra's cell population depends on dividing cells influencing cell loss, and that similar mechanisms are involved in the rejection of a graft and the separation of a bud.

Amputation, Surgical↗