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Biomedical subjects

A Ford

Publications and source records attributed to A Ford.

At least 19 recordsLinked to original sources

Rapid detection of BCR/ABL and PML/RARA using fluorescence in situ hybridization in cytospin preparations.

Fluorescence in situ hybridization (FISH) is increasingly used as an adjunct to conventional cytogenetic analysis in the diagnosis of haematological malignancies and in monitoring minimal residual disease. FISH, however, is generally performed on slides prepared after short-term sample incubation and therefore, whilst faster than conventional cytogenetics, still requires a minimum of 2 days for a result to be obtained. A simplification of the FISH procedure is reported using uncultured cytospin preparations of bone marrow or peripheral blood for the rapid diagnosis of the BCR-ABL and PML-RARa gene rearrangements. It demonstrates that culturing has no effect on the ratio of normal to abnormal cells in the nondividing population. Data is presented from an analysis of 24 cases in whom unequivocal results were obtained in less than 12 h and in complete concordance with results obtained by conventional cytogenetics and/or interphase FISH.

Bone Marrow↗

Localization of ATP-gated P2X2 and P2X3 receptor immunoreactive nerves in rat taste buds.

P2X receptors have been suggested to play a role in the transduction of sensory signals such as pain and sound. In the present study, polyclonal antibodies against P2X1 to P2X6 receptors were used to localize P2X receptors in circumvallate and fungiform papillae of rats. Nerve fibres innervating the taste buds stained intensely with P2X3 receptor antibodies. P2X3 receptor-positive nerves were observed in the intra- and subgemmal regions. The nerve fibres were also stained with P2X2 receptor antibodies, but the intensity was much lower. The distribution of P2X2 receptor immunoreactivity overlaps with that of P2X3. These results suggest that ATP might be a neurotransmitter in taste reception cells in the taste buds, where it transducts the taste signals to the afferent taste nerves by activating P2X receptors at the synapses. This is the first experiment indicating such a role for ATP, although supplementary functional studies are required.

Adenosine Triphosphate↗

HTLV-I induced intestinal lymphoma.

We document an unusual case of HTLV-I positive adult T-cell leukaemia lymphoma (ATLL) in a 25 year old Chilean patient who presented with primary small intestinal involvement and during evolution developed a leukaemic phase. Duodenal biopsy showed infiltration by pleomorphic lymphoid cells with a CD45RO+ CD20- phenotype. Circulating lymphocytes had a convoluted nucleus and displayed a mature T-cell phenotype: CD2+, CD3+, CD4+, CD8-, CD25+, HLA-Dr+. HTLV-I serology was positive and HTLV-I retroviral sequences were demonstrated by PCR in the tissue. The patient was treated with chlorambucil and is well, disease free five years from diagnosis. Intestinal lymphoma as initial manifestation of ATLL is extremely uncommon, but when a T-cell lymphoma is detected in this localisation, in patients from a HTLV-I endemic area, retroviral studies are recommended in order to exclude an association with this retrovirus.

Adult↗

Localization of ATP-gated P2X2 receptor immunoreactivity in the rat hypothalamus.

Previous pharmacological studies have indicated that ATP receptors may be involved in the regulation of physiological functions in hypothalamus. In the present study, the distribution of P2X2 receptor in the rat hypothalamus was studied with immunohistochemistry. It was shown that P2X2 immunoreactivity-positive neurons and nerve fibres were localized in many hypothalamic nuclei. Intense labelling of both neuronal cell bodies and nerve fibres was observed in the paraventricular nucleus, arcuate nucleus, retrochiasmatic area, periventricular nucleus, and the ventral part of tuber cinereum area. In supraoptic, circular, and ventral tuberomammillary nuclei the neuronal cell bodies were strongly positive, but few nerve fibres were positive. Axons with strong P2X2 immunoreactivity were found in the organum vasculosum of the lamina terminalis and median eminence. Some scattered positive neurons and nerve fibres were found in many hypothalamic nuclei including preoptic nucleus. The results of the present study demonstrated the existence of P2X receptors in hypothalamus, as a basis for detailed studies of the roles of P2X receptors in the regulation of hypothalamic functions.

Adenosine Triphosphate↗

Aspergillus fumigatus conidia induce a Th1-type cytokine response.

The response of human peripheral blood mononuclear cells (MNC) to Aspergillus fumigatus in vitro was evaluated. In studies of the proliferative response of MNC from 18 healthy donors to heat-killed A. fumigatus conidia, 15 displayed a significant response, with a stimulation index (SI) between 4 and 193. In contrast, all donors displayed a positive response to Candida albicans blastoconidia (SI ranged from 10 to 224). Despite the variability in reactivity to A. fumigatus conidia, the response of a particular individual was stable when retested over periods of 1-2 weeks. Supernatant from cocultures of A. fumigatus conidia with MNC contained increased levels of interferon-gamma, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, and interleukin (IL)-2, compared with unstimulated cells, but not IL-10 or IL-4. In addition, A. fumigatus induced lymphocyte surface expression of adhesion/activation-associated molecules. These results suggest that lymphocytes may contribute to host defense against Aspergillus by generating a Th1-type response.

Antigens, CD↗

Postnatal growth in infants born between 700 and 1,500 g.

Our purpose was to examine postnatal growth in very low birth weight (VLBW) infants (n = 54). A high frequency of intrauterine growth retardation was noted that was corrected by plotting birth weight against crown-heel length and not gestational age. No differences in postnatal growth were noted between infants whose size was appropriate for gestational age (n = 37) and those small for gestational age (n = 17). Overall, growth tended to exceed that previously published. Weight but not length or head gain was less in the smaller (< or = 1,000 g) when compared to the larger (> 1,000 g) VLBW infant. Poorer weight gain could not be related to more "illness" or less nutrient intake in the smaller infants.

Aging↗

The gene for erythropoietin receptor is expressed in multipotential hematopoietic and embryonal stem cells: evidence for differentiation stage-specific regulation.

The principal regulator of erythropoiesis is the glycoprotein erythropoietin, which interacts with a specific cell surface receptor (EpoR). A study aimed at analyzing EpoR gene regulation has shown that both pluripotent embryonal stem cells and early multipotent hematopoietic cells express EpoR transcripts. Commitment to nonerythroid lineages (e.g., macrophage or lymphocytic) results in the shutdown of EpoR gene expression, whereas commitment to the erythroid lineage is concurrent with or followed by dramatic increases in EpoR transcription. To determine whether gene activity could be correlated with chromatin alterations, DNase-hypersensitive sites (HSS) were mapped. Two major HSS located in the promoter region and within the first intron of the EpoR gene are present in all embryonal stem and hematopoietic cells tested, the intensities of which correlate well with EpoR expression levels. In addition, a third major HSS also located within the first intron of the EpoR gene is uniquely present in erythroid cells that express high levels of EpoR. Transfection assays show that sequences surrounding this major HSS impart erythroid cell-specific enhancer activity to a heterologous promoter and that this activity is at least in part mediated by GATA-1. These data, together with concordant expression levels of GATA-1 and EpoR in both early multipotent hematopoietic and committed erythroid cells, support a regulatory role of the erythroid cell-specific transcription factor GATA-1 in EpoR transcription in these cells. However, the lack of significant levels of GATA-1 expression in embryonal stem cells implies an alternative regulatory mechanism of EpoR transcription in cells not committed to the hematopoietic lineage.

Animals↗

Management of acute asthma attacks in general practice.

A prospective study was carried out in a semirural group practice between June 1988 and December 1989 to investigate acute asthmatic attacks treated with nebulized salbutamol. Questionnaires were completed by the attending doctor and by the patient (or his or her parent). Sixty nine episodes, occurring in 52 patients, were recorded during the 18 month study period. The majority of the attacks were managed exclusively in the community, with hospital admission occurring on only three occasions, one patient being admitted twice. A large proportion of the patients had a severe attack of asthma as judged by their previous history. Oral steroids were prescribed in 62.3% of attacks, oral theophyllines in 31.9% and antibiotics in 37.7%; the salbutamol nebulizer was used on more than one occasion during 41.2% of attacks. Significant morbidity was experienced by the patients during the studied attack, with 85% suffering sleep disturbance and two thirds being unable to attend work or school. Only 52.5% of patients were on prophylactic treatment and 37.5% of the patients had discontinued some aspect of their asthma therapy in the three months prior to the attack. Patients' and doctors' views about the cause of the attacks differed widely: patients most commonly cited infection (26/41) and allergy (8/41) with only two patients citing poor compliance or inadequate treatment. Although doctors also attributed the cause of many attacks to infection (33/64), they cited poor compliance or inadequate treatment in 28 of 64 responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Evaluating an RN/co-worker model.

In 1988 the University of Kentucky Hospital implemented a nurse extender model to cope with diminishing RN resources. After a year and a half of operation the model was evaluated in terms of training costs, retention, personnel costs, RN and co-worker satisfaction, and impact on quality of care. The authors conclude that although it has some limitations, the Co-worker Model allowed patient beds to remain open while minimally affecting quality.

Evaluation Studies as Topic↗

The international collaborative study on the first international standard of birch (Betula verrucosa)-pollen extract.

A selected candidate international standard preparation of birch (Betula verrucosa)-pollen extract was studied together with other birch-pollen extracts in a multinational study involving 20 laboratories in 11 countries. The biologic activity of the extract had previously been demonstrated in quantitative skin prick testing. The study methods comprised RAST inhibition, histamine release, quantitative immunoelectrophoresis, isoelectric focusing, and other methods. The results from RAST inhibition were calculated as parallel-line assays with statistical tests for linearity and parallelism. Analysis of variance was applied to test the significance of differences between potency estimates. In all assay methods, the candidate standard could be used to assign relative potencies to other birch-pollen extracts. The candidate standard was adequately stable during 36 months of storage at or below 5 degrees C. On the basis of this study, the World Health Organization has established the preparation as the International Standard for birch-pollen extract with assigned units of 100,000 IU per ampule.

Binding, Competitive↗

Clinical applications of immunocytochemistry in the monitoring of the bone marrow in small cell lung cancer (SCLC).

A panel of monoclonal antibodies (MAbs) has been identified which may be useful in detecting SCLC tumour cells and which does not cross-react significantly with normal marrow elements. Compared with conventional techniques this MAb panel markedly increases detection of micrometastases in the bone marrow especially in limited disease and post-chemotherapy in responding patients. There is a close correlation between immunological positivity and the ability to grow SCLC-like cells for variable periods in serum-free culture. In 4 cases SCLC-like cells have been characterized by electron microscopy or by the establishment of SCLC cell lines in continuous culture. The prognostic importance of pre-treatment detection of marrow involvement is unknown. The implications of post-chemotherapy detection of micrometastases are also uncertain but there may be an association with early systemic relapse which may occur regardless of intervention, including high dose intensification with autologous marrow rescue with primary site and CNS prophylactic irradiation.

Antibodies, Monoclonal↗

The collaborative study of the international standard of dog, Canis domesticus, hair/dander extract.

A collaborative study was carried out to assess the suitability of a chosen preparation to serve as the international standard (IS) for dog (Canis domesticus) hair/dander extract. Sets of five coded preparations of dog extract, including the proposed IS, were delivered to each participating laboratory in glass-sealed ampules. Fifteen laboratories in nine different countries examined the preparations by RAST inhibition, crossed immunoelectrophoresis/crossed radioimmunoelectrophoresis, histamine release, and by other methods. In spite of the use of different versions of methods and different reagents, quite consistent results were obtained, and the proposed IS was found to have a satisfactory activity in all assays and to be useful as a calibrator when allergenic potency of similar dog allergenic extracts was estimated. Four laboratories estimated the specific content of allergens Ag 3, Ag 13, and albumin and found the proposed IS to be a suitable standard for these assays. On the basis of the results from this study, the World Health Organization established the preparation as the international standard for dog hair/dander extract with an assigned unitage of 100,000 IU per ampule. The units refer to both the total allergenic activity of the ampule and to that of individual allergens.

Allergens↗

Standardization of rye-grass pollen (Lolium perenne) extract. An immunochemical and physicochemical assessment of six candidate international reference preparations.

Six candidate extracts of Lolium perenne (rye-grass) pollen have been studied in 6 laboratories using a variety of immunochemical and physicochemical techniques. Radioallergosorbent test inhibition, crossed immunoelectrophoresis, crossed radio-immunoelectrophoresis, sodium dodecyl sulphate-polyacrylamide gel electrophoresis combined with immunoblot, thin-layer isoelectric focusing and enzyme-linked immunosorbent assay inhibition were used to evaluate each of the coded extracts. The source materials were also studied for identity and possible contamination by light microscopy. On the basis of these data, the Rye-Grass Working Party recommended to the Steering Committee of the Allergen Standardization Subcommittee of the International Union of Immunological Societies that the extract coded C be chosen as the candidate international reference preparation.

Allergens↗