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Biomedical subjects

A Gray

Publications and source records attributed to A Gray.

At least 145 records · Page 8Linked to original sources
PubMed1995

Differential transcription and expression of ornithine decarboxylase in embryos of replicated mouse lines divergently selected for lean body mass.

Embryos of replicated mouse lines divergently selected for high or low lean body mass have been shown to differ approximately twofold in the activity of ornithine decarboxylase during embryogenesis and that this difference has been shown to be associated with a restriction enzyme polymorphism in the structural gene [Gray and Tait (1993) Genet. Res. 62, 31-37]. In the present paper we report that the differences in enzyme activity are due to changes in transcription and show that the enzyme produced has the same specific activity in all selected lines, precluding any significant structural change in the enzyme being associated with the differences in the structural gene.

Animals↗
PubMed1995

Trypanosoma brucei brucei: uptake and metabolism of pyridoxine and pyridoxal.

The uptake and metabolism of the B6 vitamers pyridoxine and pyridoxal by T. brucei (TREU 55) was investigated. The results show that these vitamers are taken up by simple diffusion followed by metabolic trapping. Both pyridoxine and pyridoxal were found to be metabolised to pyridoxal phosphate in whole cells. The majority of pyridoxal taken up appears to remain as pyridoxal (perhaps protein bound) the remainder being slowly phosphorylated to pyridoxal phosphate by pyridoxal kinase. The majority of pyridoxine taken up was found to be rapidly metabolised to pyridoxal. Evidence was also found supporting the hypothesis that pyridoxine may be phosphorylated to pyridoxal phosphate and then rapidly converted to pyridoxal phosphate.

Alkaline Phosphatase↗
PubMed1995

Consistent correction of data for aboriginal populations.

"A consistent correction procedure is used to determine improved, consistent estimates by sex of census age distributions, intercensal births, intercensal deaths and net migration by age for the Aboriginal populations of the Northern Territory, South Australia and Western Australia during the period 1986-91. Undercount estimates and life tables show the Aboriginal populations to have lower coverage in statistical collections and much higher death risks than the total Australian population. Inter-regional net migration estimates show that component of change can no longer be ignored."

Age Distribution↗
PubMed1995

The evolving role of radiation therapy in paediatric oncology, Philadelphia, USA, 19-21 January 1995.

A summary of a conference reviewing recent developments and changes in the use of radiation therapy in paediatric oncology is reported. Although the use of radiation therapy has resulted in improved cure rates, the long-term complications of radiation in a paediatric population are recognised. More intensive systemic therapy and the increasing availability of prognostic data, including biological markers to tailor therapy to the individual patient, has resulted in a more selective use of radiation therapy. Changes in the management of specific tumour types are discussed.

Child↗
PubMed1995

The cost of insulin-dependent diabetes mellitus (IDDM) in England and Wales.

This study estimates the direct health and social care costs of insulin-dependent diabetes mellitus (IDDM) in England and Wales in 1992 to be 96 million pounds, or 1021 pounds per person in a population with IDDM estimated at 94,000 individuals. These costs include insulin maintenance, hospitalization, GP and out-patient consultations, renal replacement therapy, and payments to informal carers. Expenditure is concentrated on younger age groups, with one-third of the total expended on those aged 0-24. Around one-half of the total costs can be directly attributed to IDDM, with the remainder associated with a range of complications of the disease. The single largest area of service expenditure is renal replacement therapy. The cost estimates are most sensitive to incidence rates of IDDM, numbers on dialysis and average duration of dialysis. A further 113 million pounds may be lost each year due to premature deaths resulting in lost productive contributions to the economy. The direct and indirect costs of IDDM are therefore significant. The cost of illness framework presented here should facilitate the economic evaluation of new and existing treatment regimens, which may improve value for money by reducing costs and/or increasing the quality or quantity of life for people with IDDM.

Adolescent↗
PubMed1995

Oculocutaneous albinism and bruising in two sisters--probable Hermansky-Pudlak syndrome.

Cases of Hermansky-Pudlak syndrome may present to the dermatologist, ophthalmologist or haematologist. Classically the diagnosis rests on the triad of oculocutaneous albinism, a bruising tendency and the presence of characteristic pigmented-containing cells in the bone marrow. Specific tests of platelet function can, however, suggest the diagnosis without recourse to invasive techniques. We describe the disease in two young sisters.

Adenosine Diphosphate↗
PubMed1995

Blood use for surgical patients: a study of Scottish hospital transfusion practices.

The use of an effective schedule for ordering blood for transfusion for surgical patients is the accepted standard of practice for hospital blood banks in UK hospitals. The use of maximum surgical blood ordering schedules (MSBOS) was surveyed throughout Scotland in 1992 and 1993. Twenty-seven hospitals participated in the study. Twenty-three (85%) of these 27 operated a schedule. Schedules varied between hospitals both in the way the schedules were implemented and in the amount of blood allocated to operations. The implementation of schedules was compared in three hospitals each for Caesarean section, transurethral resection of the prostate (TURP) and primary hip replacements. Adherence to the schedules averaged 76% (range 10-100%) and varied with operation, tariff, and hospitals. Blood use per operation did not depend on the amount of blood allowed by the schedule. Use of a MSBOS does not appear to influence clinical use of blood for transfusion, indicating that the gains in efficient use of laboratory resources and in safe handling of blood units can be made without compromising patient care.

Blood Banks↗
PubMed1995

Differences in hospital casemix, and the relationship between casemix and hospital costs.

BACKGROUND: The aim of the study was to examine the relationship between hospital costs and casemix, and after adjustment for casemix differences, between cost and institutional size, number of specialties, occupancy and teaching status. METHODS: A retrospective analysis of all admissions to nine acute-care NHS hospitals in the Oxford region during the 1991-1992 financial year was undertaken. All episodes were assigned to a diagnosis-related group (DRG) and a cost weight assigned accordingly. Costs per finished consultant episode, before and after adjustment for casemix differences, were analysed at the hospital and specialty level. RESULTS: Casemix differences were significant, and accounted for approximately 77 per cent of the difference in costs between providers. Costs per casemix-adjusted episode were not significantly associated with differences in hospital size, scope, occupancy levels or teaching status, but sample size was insufficient to investigate these relationships adequately. Specialty costs were poorly correlated with specialty casemix. This was probably due to poor apportionment of specialty costs in hospital accounting returns. CONCLUSIONS: Casemix differences need to be taken into account when comparing providers for the purposes of contracting, as unadjusted unit costs may be misleading. Although the methods used may currently be applied to most NHS hospitals, widespread use would be greatly facilitated by the development of indigenous cost weights and better routine hospital data coding and collection.

Bed Occupancy↗
PubMed1994

Inheritance of P element and reporter gene sequences in zebrafish.

We have established 15 separate lines of zebrafish transgenic for two plasmid DNAs containing Drosophila P element sequences and either the reporter genes chloramphenicol acetyltransferase (CAT), neomycin phosphotransferase (NPT), and beta-galactosidase (BGAL) or the reporter gene hygromycin phosphotransferase (HPT). Transient expression of CAT, but not NPT or BGAL, could be measured in the G0 (microinjected) generation, while expression in subsequent generations was below the limit of detection for CAT and NPT. All 15 lines contain stable low copy number integrations of between one and five transgene copies per cell with characteristic Southern blot "junction fragments" and have shown Mendelian inheritance after the G1 generation. The transgenes in 13 of 15 of the lines were originally inherited by about 10% or less of the G1 fish, suggesting a mosaic integration into the germline. Of 14 tested lines, none is associated with an embryonic recessive lethal phenotype as scored in the G3 generation.

Animals↗
PubMed1993

Measuring the impact of menopausal symptoms on quality of life.

OBJECTIVE: To examine the impact of menopausal symptoms on the overall quality of life of women. DESIGN: Data collection with a questionnaire administered by an interviewer, incorporating two different quality of life measurement techniques (time trade off and rating scale). SETTING: Specialist menopause clinic and two general practices in Oxford. SUBJECTS: 63 women aged 45-60 years recruited opportunistically during a clinic or appointment with a general practitioner; no exclusion criteria. RESULTS: Subjects gave very low quality of life ratings for health states with menopausal symptoms. The time trade off method of measuring preferences for these health states (on a scale from 0 to 1, where preference for full health is given as 1) yielded utility values of 0.64 for severe menopausal symptoms and 0.85 for mild symptoms. The rating scale measurement technique yielded even lower values: utilities of 0.30 and 0.65 were obtained for severe and mild symptoms respectively. Kappa scores indicated that the two methods produced results that were poorly related but not contradictory. Comparison of quality of life ratings before and after treatment with hormone replacement therapy showed significant improvements: with the rating scale measurement technique mean increases in utility values after the relief of severe and mild menopausal symptoms were 0.56 and 0.18 respectively. CONCLUSIONS: Quality of life may be severely compromised in women with menopausal symptoms, and perceived improvements in quality of life in users of hormone replacement therapy seem to be substantial. This emphasises the need to include quality of life measurements when assessing outcomes of hormone replacement therapy. Several limitations may exist with widely applied measurement techniques, calling for the development of appropriate and well validated instruments for measuring quality of life associated with reduced health states.

Data Collection↗
PubMed1993

Aboriginal population prospects.

The authors examine data from the 1986 and 1991 Australian censuses to assess discrepancies between the census data and past projections of the size and structure of the Aboriginal population. They also "comment on ways in which determinants of Aboriginal population change are diverging from the parameters used for previous projections. We pay particular attention to mortality prospects.... We note the evidence for under-enumeration of the Aboriginal population in particular age groups in the 1991 Census as in previous censuses, and estimate the size of adjustments necessary to correct for some, but not all, of these deficiencies. The analysis shows that Aboriginal fertility increased in the second half of the 1980s."

Age Distribution↗
PubMed1993

AJ-p90: a novel protein of the perinuclear theca in human sperm subacrosome.

A perinuclear theca protein of the human sperm subacrosome was detected using LH43 monoclonal antibody which was originally raised against human keratinocytes. Using indirect immunofluorescence, the antibody stained the acrosomal zone (AZ) of dried ejaculated spermatozoa but did not react with viable cells, thus suggesting that the antigen was intracellular. This was confirmed by immunogold electron microscopy which also revealed the ultrastructural localisation of the antigen to the subacrosomal fibrils. Throughout spermatogenesis the antigen was only detected on the AZ of developed testicular spermatozoa and its expression was continued during their epididymal passage. Biochemically, the protein was insoluble in Triton, and dithiothreitol (DTT) was required for its solubilisation. In Western blotting of sperm and keratinocyte lysates, the antibody detected similar 90-kDa protein doublets (AJ-p90). These biochemical features exclude the identity of AJ-p90 with various cyto- and karyo-skeletal antigens, including the intermediate filaments and microfilaments. AJ-p90 therefore represents a novel product of the subacrosomal perinuclear theca. The significance of these data is discussed together with the importance of the antibody for probing the perinuclear theca in normal and abnormal germ cells, including multinucleated spermatids which also showed reactivity with the antibody.

Acrosome↗
PubMed1993

Antigenic determinants of human sperm tail fibrous sheath proteins.

Mouse anti-fibrous sheath antisera (MAFA) produced by immunizing mice with purified preparations of human sperm tail fibrous sheath (FS) reacted with the principal piece of less than 10% of freshly isolated spermatozoa which were immotile and probably dead. Following their demembranation by detergents or repeated freezing and thawing, all spermatozoa were stained. This was also demonstrated on spermatozoa dried onto slides, but the undiluted xenoantisera showed additional reactivity with the acrosomal zone (AZ). Using immunogold electron microscopy, the target antigens were ultrastructurally localized to the FS, and a few spermatozoa showed some reaction at the AZ subacrosomal perinuclear theca. Following titration of the antibodies, the anti-AZ-reaction became undetectable at a dilution of 1:20 while their reactivity with the principal piece continued to a 1:400-dilution. These results indicated that the xenoantisera probably contained an additional unrelated antibody component which reacted with the AZ. Western blotting and staining of purified FS with MAFA detected seven major protein bands with MW ranging between 25 kDa and 97.4 kDa. In human testes, the 1:50 diluted MAFA reacted with sperm tails only, indicating the late expression of the antigenic determinants during spermatogenesis. MAFA did not react with oesophagus, stomach, duodenum, ileum, nasal lining tissues, uterus, pericardium, pancreas, thyroid gland, or cultured fibroblasts. The xenoantisera did, however stain the skin epidermis and cultured keratinocytes which exhibited filamentous cytoplasmic staining although their target antigens could not be biochemically identified. These results indicate that the FS proteins express antigenic determinants which are not shared with other cytoskeletal elements within the sperm flagellum or a variety of somatic tissues.

Animals↗
PubMed1993

Impaired antibody diffusion within the cytoplasmic membrane-fibrous sheath interspace of the human sperm tail.

Monoclonal and polyclonal antibodies specific for the fibrous sheath (FS) were used to assess their diffusion within the subcytoplasmic membrane space of the human sperm tail. Using indirect immunofluorescence (IIF) and immunogold electron microscopy (IEM), the staining of the entire FS with these antibodies was observed only when the spermatozoa were completely demembranated by detergents or dried onto slides. Partial damage to sperm cytoplasmic membranes by freezing and thawing resulted in segmental staining of the FS. The IEM of such spermatozoa with the antibodies revealed the distribution of gold particles on the FS in denuded areas only and adjacent segments which retained their cytoplasmic membrane were not stained. These results indicate that partial disruption of the sperm plasma membranes does not lead to free diffusion of antibodies within the cytoplasmic membrane-FS interspace. This property appears to be unique to sperm cells and is due to their specialized structural organization.

Antibodies↗
PubMed1993

Identification of ornithine decarboxylase as a trait gene for growth in replicated mouse lines divergently selected for lean body mass.

Studies of lines of mice selected for body mass have shown that there is a significant genetic component affecting this trait although the nature of the genes involved remains to be elucidated. Using replicate lines of mice, our studies have shown that two different variants of the mouse ornithine decarboxylase (ODCase) gene have been selected in replicate lines of mice selected for high and low lean body mass respectively. One variant is associated with an increased peak of ODCase activity in embryos (10-13 days of gestation) in all high mass lines and with a restriction fragment length polymorphism of the expressed gene. The increased ODCase activity coincides with increased ODCase mRNA levels in the high mass selected lines. These results provide evidence implicating ornithine decarboxylase as a major factor in cell growth, and as a candidate 'trait gene'.

Animals↗