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Biomedical subjects

A Pollock

Publications and source records attributed to A Pollock.

At least 19 recordsLinked to original sources
PubMed1995

Privatisation by stealth?

'Government lights the fuse for privatisation' blazed the Health visitor journal's front cover when the NHS and Community Care Act was passed in 1990. Since then the debate on the future of the NHS has raged. In the first of a series in which different authors look at policy issues, Allyson Pollock argues that the introduction of charges for dentistry, eye tests and long-term care--is undermining the principle of a universal national healthcare service, free at the point of use.

Fees, Medical↗
PubMed1994

Philadelphia chromosome positive acute lymphoblastic leukemia masquerading as persistent asymptomatic bone marrow necrosis.

Bone marrow necrosis is an uncommon histologic finding of malignant diseases at presentation. Clinically it is characterized by pyrexia and severe bone pain, and heralds a poor prognosis if untreated. We report an unusual patient with asymptomatic bone marrow necrosis persisting for 10 mths, a hitherto undescribed length of time for this condition. The diagnosis of Philadelphia chromosome positive acute lymphoblastic leukemia was finally made after multiple bone marrow biopsies.

Aged↗
PubMed1994

A prospective study of the prevalence of clear-cut endocrine disorders and polycystic ovaries in 350 patients presenting with hirsutism or androgenic alopecia.

OBJECTIVE: To determine the frequency of polycystic ovaries (PCO) on ultrasound and the incidence of clearcut endocrine disorders leading to virilization in patients complaining of hirsutism or androgenic alopecia. The major purpose was to determine a coherent policy for the routine biochemical assessment of such women. DESIGN: A prospective study of women attending a joint skin/endocrine clinic complaining of these problems. PATIENTS: Three hundred and fifty consecutive women with hirsutism and/or androgenic alopecia were assessed. MEASUREMENTS: Baseline endocrine screens were conducted on two occasions and included measurement of serum testosterone, androstenedione, dehydroepiandrosterone sulphate, sex hormone binding globulin, LH, FSH, 17-hydroxyprogesterone and PRL. The ovaries were visualized by high-resolution pelvic ultrasound scanning. RESULTS: Eight women were identified with relevant endocrine disorders; of these, one was acromegalic and one had a microprolactinoma--in both cases the association may have been fortuitous. Three had clear-cut 21-hydroxylase deficiency, one a rare hepatic enzyme deficiency (11-reductase), one a virilizing adrenal carcinoma and one a Leydig cell tumour. The latter six cases all had persistently elevated levels of serum testosterone (> 5 nmol/l). In all, 13 women had baseline testosterone levels in excess of 5 nmol/l. Polycystic ovaries were present in 81% of the cases who had erratic cycles and 52% of those with regular cycles; PCO were present in two of the women with 21-hydroxylase deficiency and in the woman with 11-oxoreductase deficiency. The Leydig cell tumour (1.2 cm diameter) was not detected on ultrasound or CT scan. CONCLUSIONS: For the exclusion of enzyme deficiencies and virilizing tumours clinical assessment and a single serum testosterone measurement will suffice.

Adult↗
PubMed1993

8;21 translocation and multilineage involvement.

The translocation (8;21)(q22;q22) is commonly associated with acute myeloid leukemia (AML) M2 according to the French-American-British (FAB) classification. We describe 11 cases of t(8;21) diagnosed by strict FAB criteria. Six cases were diagnosed as AML M2, 3 cases as AML M4, 1 case as refractory anemia with excess of blasts in transformation, and 1 case as Philadelphia chromosome negative chronic myeloid leukemia in acceleration. Translocation (8;21) could thus occur in a wider variety of hematological abnormalities. Accordingly, we propose that t(8;21) may involve different hemopoietic lineages.

Acute Disease↗
PubMed1992

Public health heresy.

Explore the source record for details and available documents.

Public Health Administration↗
PubMed1992

Semantic additivity and semantic inhibition: dissociable processes in the cerebral hemispheres?

We report the results of two visual half-field semantic priming experiments using a high proportion of related trials to examine hemisphere asymmetries for semantic processes beyond those attributable to automatic meaning activation. Contrary to previous investigations, we obtained inhibition for unrelated trials in both visual fields. However, priming was additive (being greater for words related via category membership and association than for either single dimension) only when words were presented to the RVF/left hemisphere. A third experiment, using centrally presented stimuli, implied that semantic additivity should be attributed to post-access meaning comparisons and inhibition to the generation of semantic expectancies. These results suggest (1) that inhibition and additivity are potentially dissociable "controlled" semantic processes and (2) that the left hemisphere predominates for meaning integration across successively presented words. The availability of finely tuned meaning integration processes in the left hemisphere may contribute to its superiority in language processing, despite right hemisphere competence for some semantic operations.

Adult↗
PubMed1992

Radioimmunoassay that measures serum vitamin B12.

AIMS: To develop a specific radioimmunoassay for the routine determination of serum vitamin B12. METHODS: Antisera were raised in rabbits by immunisation with the monocarboxylic acid derivative of cyanocobalamin coupled to human serum albumin. Antibody titres and affinities were determined and the antiserum giving the highest binding affinity constant, Ka, was used to develop the assay protocol. Donkey-anti-rabbit gamma globulin-coated magnetisable particles were used to separate the bound from free vitamin B12. The considerable cobalamin binding capacity of human serum was destroyed by autoclaving in acetate-cyanide buffer. Sixty samples were assayed by the radioimmunoassay (RIA) and the Lactobacillus leichmannii assay. Recovery and cross-reactivity experiments were performed. RESULTS: Final rabbit antibody titres varied from 1/20,000 to 1/188,000. Scatchard plots did not correlate with the antibody titres. The Ka values varied from 2.6 to 6.7 x 10(10) litres/mol. For maximum sensitivity the highest Ka (titre 1/66,000) was chosen. A tracer concentration of 22 pmol/l, an antiserum dilution of 1/100,000, and a sample volume of 0.1 ml were used. At an antiserum dilution of 1 in 100,000 the cyanocobalamin binding of the rabbit serum was diluted out. The assay showed excellent correlation with the microbiological assay, with 100% recovery of added vitamin B12. Levels of cross-reactivity for dicyanide cobinamide and hydroxocobalamin were 9.8 and 8.1%, respectively. CONCLUSIONS: The development of this immunoassay permits the measurement of serum vitamin B12 without important interference from cobalamin analogues, related corrinoids, and non-specific binders.

Animals↗
PubMed1992

Use of technicon H*1 technology in routine thalassaemia screening.

In a retrospective study of 36 cases of alpha-thalassaemia trait, 43 cases of beta-thalassaemia trait and 45 cases of iron deficiency, we have assessed the performance of the Technicon H*1 erythrogram, the hypochromia minus microcytosis (H-M) index, and the discriminant function (DF). The diagnostic accuracy of the erythrogram pattern was 83.3% for alpha-thalassaemia trait and 95.3% for beta-thalassaemia trait. The diagnostic accuracy for the H-M index was 19.4% for alpha-thalassaemia trait, 72.1% for beta-thalassaemia trait and 91.1% for iron deficiency. By comparison, the DF gave a diagnostic accuracy of 75.0% for alpha-thalassaemia trait, 81.4% for beta-thalassaemia trait and 88.9% for iron deficiency when using a locally derived value for the constant (k) = 19.2. Our study shows that the H*1 erythrogram pattern, the H-M index and the DF are useful predictive indicators in routine laboratory screening for thalassaemia.

Discriminant Analysis↗
PubMed1992

The significance of neopterin and biopterin concentrations at presentation in haematological malignancies.

Urinary neopterin and biopterin concentrations were measured in 32 healthy controls and 53 patients with newly diagnosed haematological malignancies classified and staged by accepted criteria. The neopterin concentrations were only significantly raised in chronic lymphocytic leukaemia at stages III-IV. Total biopterin concentrations after oxidation with iodine at acid pH were decreased in chronic lymphocytic leukaemia stages O-II, multiple myeloma, and acute myeloid leukaemia but not in chronic lymphocytic leukaemia stages III-IV. Although of research interest, neopterin concentrations proved of little prognostic value at presentation, but taken with the biopterin concentration they may be useful for the assessment of tumour activity.

Biomarkers, Tumor↗
PubMed1990

Semantic and associative priming in the cerebral hemispheres: some words do, some words don't ... sometimes, some places.

This study investigated spreading activation for words presented to the left and right hemispheres using an automatic semantic priming paradigm. Three types of semantic relations were used: similar-only (Deer-Pony), associated-only (Bee-Honey), and similar + associated (Doctor-Nurse). Priming of lexical decisions was symmetrical over visual fields for all semantic relations when prime words were centrally presented. However, when primes and targets were lateralized to the same visual field, similar-only priming was greater in the LVF than in the RVF, no priming was obtained for associated-only words, and priming was equivalent over visual fields for similar + associated words. Similar results were found using a naming task. These findings suggest that it is important to lateralize both prime and target information to assess hemisphere-specific spreading activation processes. Further, while spreading activation occurs in either hemisphere for the most highly related words (those related by category membership and association), our findings suggest that automatic access to semantic category relatedness occurs primarily in the right cerebral hemisphere. These results imply a unique role for the right hemisphere in the processing of word meanings. We relate our results to our previous proposal (Burgess & Simpson, 1988a; Chiarello, 1988c) that there is rapid selection of one meaning and suppression of other candidates in the left hemisphere, while activation spreads more diffusely in the right hemisphere. We also outline a new proposal that activation spreads in a different manner for associated words than for words related by semantic similarity.

Adult↗