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Biomedical subjects

A Green

Publications and source records attributed to A Green.

At least 325 records · Page 18Linked to original sources
PubMed1994

Extramedullary haemopoiesis in fetal and adult human spleen: a quantitative immunohistological study.

Haemopoietic cells were assessed in spleens from normal adults, adults with splenic extramedullary haemopoiesis due to chronic myeloproliferative disorders and fetuses of 17-21 weeks' gestation. A variety of antigens expressed by developing granulocytes and erythrocytes were demonstrated immunohistochemically. The relative proportions of early and late precursor cells of these two lineages were quantified. There was no significant haemopoiesis in normal adult spleen, while there was abundant (predominantly granulocytic) haemopoiesis in patients with chronic myeloproliferative disorders. Fetal spleens contained numerous late erythroid precursors but few early erythroid or granulocytic cells. The relative numbers of early and late haemopoietic cells in adult chronic myeloproliferative disorders and fetal spleens showed statistically significant differences. Our findings indicate that haemopoiesis in the spleens of adult patients with these disorders differs fundamentally from that occurring in fetal life. They support the view that the human spleen does not have a significant role in fetal haemopoiesis, but that it filters circulating nucleated erythroid precursors and is permissive of their terminal differentiation only. Our results also favour the view that adult splenic haemopoiesis originates by displacement of precursor cells from the bone marrow rather than by activation of stem cells which have lain dormant in the spleen since fetal life.

Adult↗
PubMed1994

Increased prevalence of insulin-treated diabetes mellitus in Funen County, Denmark.

OBJECTIVE: To determine the prevalence of insulin-treated diabetes mellitus in Funen County, Denmark as of 1 July 1987 and compare the findings with those of a similar study from 1973. DESIGN: The population was identified by insulin prescriptions collected during a 1 year period. The identity of the prescription holders, the diagnosis and the date of diagnosis were verified from medical records and public registers. RESULTS: The estimated degree of ascertainment of the material is 0.95-0.97. The prevalence rates (per 1000 of the population) of insulin-treated diabetes mellitus as of 1 July 1987 are: 4.74 (95% Cl 4.66-4.82) for all cases, 2.08 (95% Cl 2.01-2.15) for the group with onset of diabetes before age 30 years and 2.66 (95% Cl 2.59-2.73) for the group with onset after age 30 years. These figures correspond to increases of 39, 26 and 51% (P < 0.001) on data collected in 1973. CONCLUSIONS: There was a significant increase in the prevalence of insulin-treated diabetes mellitus in Funen County, Denmark from 1973 to 1987. Analysis of the data shows that an important factor for this increase is a liability to start insulin treatment of type 2 (non-insulin-dependent) diabetes mellitus at an earlier stage than previously. Also, the data suggest that improved prognosis for diabetic patients as well as an increasing incidence of diabetes mellitus are factors involved in the increase.

Adolescent↗
PubMed1994

What causes basal cell carcinoma to be the commonest cancer?

We conducted a hospital-based case-control study in Brisbane, Queensland, to investigate the specific determinants of basal cell carcinoma (BCC), as distinct from squamous cell carcinoma (SCC), with emphasis on ancestry, residential history, pigmentary characteristics, sun sensitivity and other constitutional factors. The sample was recruited from a dermatology outpatient clinic during an eight-week period in 1991, and comprised 51 incident or recently diagnosed cases of BCC, and 112 randomly selected controls with no known history of BCC or SCC. Twenty-six cases with both BCC and SCC were analysed separately. We found no risk factor specific to BCC which might explain its extremely high prevalence. The strongest risk factors for BCC were advanced age, male sex and a propensity to freckle (independent of skin colour and tendency to burn), all of which have previously been observed for SCC. A finding not previously reported was an apparent protective effect of increasing body mass, specific to BCC alone.

Aged↗
PubMed1994

Melanocytic lesions excised from the skin: what percentage are malignant?

We estimated the diagnostic skill of clinicians managing melanocytic skin naevi by measuring the percentage of malignant melanomas, premalignant and potentially malignant naevi, in 1896 excised melanocytic lesions submitted to a pathology service over 11 weeks. They comprised 8 per cent. The percentage increased with age: 4 per cent in the under-40s, 17 per cent in those aged 40-59, and 30 per cent in those over 60, (P < 0.001, sex-adjusted). Although the percentage was twice as high in males (11 per cent) as females (6 per cent), after adjustment for age the difference was not significant. Invasive melanomas, 3 per cent of the total, were similar: 1 per cent were from under-40s; 7 per cent from those aged 40-59 years; and 14 per cent from those over 60. They comprised 4 per cent of lesions from males and 2 per cent from females. These trends may indicate poor specificity of clinical diagnosis, notwithstanding other reasons for removal of naevi (cosmetic), particularly among patients under 40, and females.

Adolescent↗
PubMed1994

Chimeric transcriptional activators generated in vivo from VnfA and AnfA of Azotobacter vinelandii: N-terminal domain of AnfA is responsible for dependence on nitrogenase Fe protein.

In vivo recombinants generating chimeras between the transcriptional activators VnfA and AnfA of Azotobacter vinelandii were constructed by cloning their structural genes in tandem and selecting against a conditionally lethal gene inserted between them. The parent molecules differ in their promoter specificities and in that AnfA, but not VnfA, requires the Fe protein of nitrogenase for its activity. Chimeras with fusion junctions in the N-terminal half of the central domain were found to be inactive, probably as a result of misfolding. All chimeras carrying the C-terminal domain of AnfA showed the corresponding promoter specificity, supporting the model which ascribes promoter specificity to the DNA-binding properties of the C-terminal domain. None of the chimeras showed the dependence on Fe protein typical of AnfA, including one which composed 82% of AnfA with only a short segment of VnfA at the N terminus. Deleting the N-terminal domain of AnfA gave a fully active protein which was also independent of Fe protein. This indicates that the N-terminal domain has an inhibitory effect on activity which is relieved by Fe protein.

Amino Acid Sequence↗
PubMed1994

Neonatal screening for phenylketonuria: evaluation of an automated enzymatic method.

An enzymatic assay for phenylalanine using phenylalanine dehydrogenase is available in kit form (Quantase) for use with dried blood spot specimens and microtitre plates. The method has been automated by use of a sample processor and its performance and suitability for neonatal screening for phenylketonuria has been evaluated by comparison with the Guthrie bacteriological inhibition assay. The enzymatic method performed well with regard to precision and accuracy. It was able to differentiate between normal and raised phenylalanine concentrations for the purpose of screening, thus greatly reducing the repeat rate for equivocal results. There were, however, some concerns about its robustness for screening and its detection limit. The Quantase assay has the potential to be used as a large-scale routine neonatal screening method, if its use can be shown to be cost-effective.

Amino Acid Oxidoreductases↗
PubMed1994

Tumor necrosis factor increases the rate of lipolysis in primary cultures of adipocytes without altering levels of hormone-sensitive lipase.

To investigate the effects of cytokines on adipocyte lipolysis, a macrophage cell line (RAW 264.7) was treated with Escherichia coli lipopolysaccharide (1 microgram/ml) for 18 h to induce cytokine release. Conditioned medium (5%, vol/vol) from these cells was added to rat epididymal adipocytes isolated and incubated under sterile conditions. After incubation, the adipocytes were washed, and the rate of lipolysis (glycerol release) was determined after a further 1-h incubation. The conditioned medium caused an approximately 2.7-fold increase in lipolysis, detectable after 6-12 h, maximal by 24 h, and reversible by 48 h after washing the cells. The effect of conditioned medium was reversed by a neutralizing antibody to mouse tumor necrosis factor-alpha (TNF alpha), and the direct addition of recombinant human TNF alpha (0.1-50 ng/ml) reproduced the effect, with a half-maximally effective concentration of approximately 3 ng/ml. The effect of TNF on the expression of hormone-sensitive lipase (HSL; the rate-limiting enzyme for lipolysis) was investigated by Western immunoblots using an antibody raised to a bacterially expressed 96-amino acid portion of the HSL enzyme. TNF treatment did not alter the concentration of immunoreactive HSL. From these data we conclude that 1) macrophages release a cytokine(s) in response to lipopolysaccharide that stimulates lipolysis in freshly isolated adipocytes; 2) TNF alpha can account for most, or perhaps all, of this effect; 3) TNF alpha increases the rate of lipolysis by a mechanism that does not involve increased expression of HSL. Based on the time-dependent aspects of TNF alpha stimulation and the lack of change in immunoreactive HSL, the findings suggest a TNF-induced posttranslational modification of the enzyme.

Adipocytes↗
PubMed1994

Decentralization and primary health care: some negative implications in developing countries.

Decentralization is a highly popular concept, being a key element of Primary Health Care policies. There are, however, certain negative implications of decentralization that must be taken into account. These are analyzed in this article with particular reference to developing countries. The authors criticize the tendency for decentralization to be associated with state limitations, and discuss the dilemma of relating decentralization, which is the enhancement of the different, to equity, which is the promotion of equivalence. Those situations in which decentralization can strengthen political domination are described. The authors conclude by setting out a checklist of warning questions and issues to be taken into account to ensure that decentralization genuinely facilitates the Primary Health Care orientation of health policy.

Developing Countries↗
PubMed1994

Suicides in men with IDDM.

OBJECTIVE: To investigate the occurrence of suicide in men with insulin-dependent diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS: A cohort of all Danish men born between 1949 and 1964 (including 1964) who were diagnosed with IDDM before age 20 (n = 1,682) was ascertained earlier. Follow-up from diagnosis to death or 1 January 1991 was based on record linkage with the Danish Civil Registration System and was supplemented with information from death certificates obtained from the Danish National Registry of Deaths. From published vital statistics, cause-specific standardized mortality ratios (SMRs), adjusted for age and calendar time, were calculated. RESULTS: Among the 168 deaths recorded during follow-up, 15 took place in connection with the onset of IDDM and have been excluded. Of the remaining 153 deaths, 12 were officially classified as suicides (SMR 12/7.48 = 1.6, 0.05 < P < 0.1); as for the age-group of 20-24 years, SMR was 2.98, P < 0.05. Furthermore, all deaths officially classified as attributable to unknown causes (n = 28) and accidents (n = 22) were reviewed with respect to unrecognized suicides; as for deaths of unknown causes, three could be reclassified as probable suicides and two as possible suicides, whereas one of the deaths caused by accident could be reclassified as possible suicide. CONCLUSIONS: Young men with IDDM may confer a higher risk of suicide than expected. Furthermore, suicide may represent an underestimated cause of death among patients with IDDM.

Adolescent↗
PubMed1994

Comparison of error rates and performance on Wechsler's Coding and Digit Symbol subtests and the Symbol-Symbol test for children and adults.

Performance on Digit Symbol, Coding, and similar symbol-substitution tests are known to be influenced by a wide variety of reversible and nonreversible organic syndromes and learning disabilities. Recently, questions regarding the interchangeability of different symbol-substitution tests have been raised. The present study compared the performance, i.e., number of substitutions completed accurately and number of errors, of 37 adults, 32 adolescents, and 45 children on the Wechsler symbol-substitution tests of Digit Symbol and Coding with their performance on the recently designed Symbol-Symbol test. Analysis indicated that, while Symbol-Symbol performance is highly correlated with Wechsler scores on symbol-substitution tests, significant differences in error rates and speed of performance suggest that the Symbol-Symbol test cannot be considered an equivalent symbol-substitution test. Further investigation of the properties and the potential uses of the Symbol-Symbol test with clinical populations must be undertaken.

Adolescent↗
PubMed1994

Group specific component in serum and otosclerosis: no association.

An earlier Swedish study suggested a positive association between otosclerosis and the group-specific component GC*1F marker. We investigated the distribution of GC subtypes in 101 Danish patients with otosclerosis who all had surgery performed in the county of Funen. Compared to 1674 Danish controls we found no evidence of any association between markers from the GC serum protein system and otosclerosis.

Female↗
PubMed1994

International experience and health sector reform: the challenge for developing health systems.

Health sector reform is a priority issue in many countries and there is great scope for an international exchange of experiences. We should not be amiss, however, to the problems and dangers of such international exchange. Focusing on the situation of developing countries, three critical problems are identified: tendencies to the universalism of a market approach, a one-way transmission of ideas, and the lack of policy analysis. In order to contribute to a more constructive process of international exchange, four recommendations are proposed in the areas of training and the approach to management, management research, strengthening health policy analysis, and developing new exchanges between countries.

Communication↗
PubMed1994

Imaging techniques for glenohumeral arthritis and glenohumeral arthroplasty.

A thorough history and physical examination can usually determine the cause of a painful shoulder. In most cases, the diagnosis and cause of glenohumeral arthritis are fairly obvious. Imaging studies such as radiographs, computed tomography (CT), arthrography, ultrasonography, and magnetic resonance (MR) imaging are used to confirm and further define the pathologic process. Early in the development of glenohumeral arthrosis, subtle radiographic findings may suggest the diagnosis when the symptoms are mild. Later in the progression of joint destruction, imaging studies are crucial to the planning of prosthetic arthroplasty. Subsequent to arthroplasty, imaging studies can identify existing or potential problems that might correlate with the clinical course. Recent advances in musculoskeletal imaging, such as CT, ultrasound, and MR imaging, enable the physician to confirm or document anatomic pathology that was previously only inferred. There has been a corresponding increase in the use of imaging modalities. Concurrently, cost has become a major concern, and its limitation or reduction a priority of current and future medical care. Consequently, the knowledge gained from further research, education, and clinical experience must promote appropriate use and enable doctors to avoid sophisticated imaging when the results will not influence the course of treatment. The radiographic evaluation of glenohumeral arthrosis the use of imaging techniques in planning prosthetic glenohumeral arthroplasty, and the role of imaging in followup evaluations of prosthetic arthroplasty are discussed. The preferred approaches to these subjects are presented and clinical cases are used to highlight the important and interesting principles.

Arthritis, Rheumatoid↗
PubMed1994

The functions of writing: transmission between generations and role assignment within the family, in Henry James and his family.

The Jameses provide abundant material for this study of the function of writing within a family, combining a relationship between generations and between the sexes among siblings. The starting point is Henry's dream of the Galerie d'Apollon, which can be referred to its sources in reality; its autobiographical account; and its transformation into a story. This material gives clues to some central features of his unconscious conflicts with both his father and elder brother. The father's writings deal with his concern with religion, which expresses his relationship with his own father. William transforms his father's theology into philosophy and becomes one of the pioneers of modern psychology. Alice's diary recounts her identification with her father's infirmity through her hysterical paralysis. Henry's work reveals that he is the one who really succeeded in solving his conflicts with the father. His literature is transgressive according to his father's and brother's values, though he shares their ideal of a consciousness common to the Jameses. Through fiction, Henry has indirect access to the drives; but only in his work did he acknowledge these, overcoming his oedipal conflicts. Thus Henry is the closest of the Jameses to psychoanalysis; his work enables us to make some hypotheses regarding the creative process.

Family↗