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Biomedical subjects

C Barron

Publications and source records attributed to C Barron.

At least 19 recordsLinked to original sources
PubMed2000

Development of a district Cord Blood Bank: a model for cord blood banking in the National Health Service.

The Bristol Cord Blood Bank was established as a pilot project within existing health services to establish cost-effective recruitment, collection and processing suitable for use in the NHS should cord blood become a routine source of haemopoietic stem cells for transplantation in the UK. An important aim of the project was to evaluate the feasibility of establishing a midwifery-based collection network, thus utilising expertise already in place. Collection was performed on the delivery suite immediately after the placenta was delivered. The clinical experience of the midwife collector/counsellors allowed rapid pre-collection assessment of the condition of the cord and placenta. This prevented collection attempts from diseased or otherwise damaged placentas, leading to conservation of resources by preventing collection of most small volume donations. The bank was established within the National Blood Service, Bristol Centre to achieve Good Manufacturing Practice standards and ensure that processing was subject to the same stringency required for other sources of haemopoietic stem cells. Cord blood is an expensive resource. By utilising existing expertise in district Obstetric and National Blood Services, the Bristol Cord Blood Bank may serve as a model for health economic evaluation of cord blood banking of volunteer donations within the NHS.

Blood Banks↗
PubMed1999

Impact of obstetric factors on cord blood donation for transplantation.

Recent reports have shown that low nucleated cell dose significantly decreases survival after cord blood transplantation. Prior to starting clinical cord blood banking we investigated the impact of obstetric factors on cell dose and volume of cord blood donations. Cord blood was obtained from 114 normal full-term deliveries. Mean volume collected was 93.5 ml, mean total nucleated cell count (TNC) was 13.1 x 108. Statistical analysis was by backwards stepwise regression. Significant factors affecting nucleated cell yield were volume of blood collected (P < 0.001), length of gestation (P < 0. 0001), time from delivery of the infant to cord clamping (P = 0.018) and total length of labour (P = 0.002). In clinical cord blood banking we have successfully used these findings for pre-collection assessment of placentae. Out of 476 cord blood donations subsequently collected for banking, only 29 (6.1%) have been discarded due to low volume. The mean TNC of the 409 banked units following volume reduction was 10.1 x 108. Despite careful optimization of collection, processing and storage techniques, cell dose still limits cord blood transplantation to smaller recipients.

Blood Banks↗
PubMed1994

Alternatively spliced mRNAs encoding soluble isoforms of the erythropoietin receptor in murine cell lines and bone marrow.

32D Epo and 32D GM cells are subclones of the murine 32D cell line which are selectively dependent for proliferation and survival on erythropoietin (Epo) or granulocyte/macrophage colony-stimulating factor (GM-CSF), respectively. 32D GM cells were previously shown to express significant levels of the Epo receptor mRNA and protein which was retained intracellularly and did not appear on the cell surface. We have now analyzed the EpoR mRNA from the 32D GM line, using PCR followed by direct sequencing. Several alternatively spliced products were detected. In some molecules, intron 5 (I5) or part of I6 or both were retained. Retention of I5 results in a mRNA potentially encoding an almost complete extracellular domain, while retention of I6 gives rise to a mRNA encoding the complete extracellular and transmembrane domains. A different type of splicing results in the loss of exon 5 (E5), giving rise to a sequence encoding a truncated extracellular domain. These alternatively spliced sequences are differentially represented in 32D Epo versus 32D GM cells. All are additionally present in normal bone marrow cells. Apart from these alternatively spliced EpoR RNAs, no other abnormalities were detected in EpoR RNA from 32D GM cells that could account for the intracellular retention of EpoR in the non-erythroid subclones of 32D.

Alternative Splicing↗
PubMed1994

Mothers' causal explanations for their son's schizophrenia: relationship to depression and guilt.

This study investigated the relationship between mothers' causal explanations for their son's schizophrenia and the depression and guilt mothers experience. Thirty-three mothers who were primary caregivers to a schizophrenic son were interviewed using the Causal Dimension Scale and the Multiscore Depression Inventory. Twenty-nine mothers generated 50 causal explanations for their son's schizophrenia. The most frequently cited causal category was physiological/biological factors. Guilt was associated with causal explanations characterized as internal, whereas depression was unrelated to causal dimensions. The findings support the need to assess mothers' causal explanations for their son's schizophrenia and to research the health consequences of causal explanations.

Adult↗
PubMed1993

Low vision rehabilitation of multiple sclerosis: a case report.

A 34-year-old white male presented with a previous diagnosis of optic atrophy secondary to multiple sclerosis, seeking low vision rehabilitation. This case report is presented to illustrate the importance of prescribing both conventional optical low vision devices, as well as computer low vision aids in order to provide comprehensive low vision rehabilitation for a young visually impaired adult.

Adult↗
PubMed1992

Transcription of the gene for the merozoite surface antigen MSA2 of the human malaria parasite Plasmodium falciparum during the asexual cycle.

The transcription of the Plasmodium falciparum gene for the MSA2 antigen has been studied throughout the parasite's asexual growth cycle. For this purpose poly(A)+ RNA from different times of the cycle was tested for the presence of the mRNA encoding MSA2 by in vitro translation and subsequent analysis of the translation products by immunoprecipitation with an antibody against MSA2. The results revealed that this mRNA is present in trophozoites, reaches the highest concentration during the transition from the trophozoite into the schizont stage, and persists until the cycle end. Minute amounts of this mRNA were also detected in rings. In addition, the data confirmed that the primary translation product is not proteolytically processed at any time of the cycle.

Animals↗
PubMed1992

An evaluation of empirically fitting a posterior toric hydrogel contact lens.

The performance of toric hydrogel contact lenses fit without the use of diagnostic trial lenses was evaluated. Fifty-four patients (107 eyes) were empirically fit with a back surface toric lens (DuraSoft 3 Optifit Contact Lens), with the contact lens prescription based solely on keratometry and refractive findings. An assessment of lens performance was based on measures of lens movement and centration, visual acuity, lens rotation, rotational stability and patient acceptance of vision. Final mean lens rotation was found to be 1.43 degrees nasal (standard deviation 5.89 degrees), with 51 percent of the eyes exhibiting no lens rotation. Seventy-five percent of the eyes achieved acuity equal to that of their best corrected spectacle acuity, and 95 percent of the eyes achieved acuity equal to or within one line of their optimal spectacle corrected acuity. These results compare favorably to previously reported success rates of fitting toric hydrogel lenses using both empirical and diagnostic fitting procedures.

Astigmatism↗
PubMed1991

Bioptic telescopic spectacles for motor vehicle driving.

Attaining independent daily living skills is the primary functional goal of low vision rehabilitation. One of the most important of these skills is the ability of the low vision patient to achieve independent travel. In many geographical areas, automobile driving is the only available means of transportation. The utilization of a bioptic telescopic spectacle (BTS) provides a mechanism for some visually impaired individuals to qualify for a driver's license. However, the use of bioptic telescopic spectacles for driving is an extremely complex and controversial issue. An overview of the current status of the driving laws in various states, the accident rates of bioptic telescopic drivers, and various alternative proposals for motor vehicle licensure for the visually handicapped will be discussed.

Automobile Driver Examination↗
PubMed1990

Going the distance: rural health care in Texas.

Many doctors and hospitals are being squeezed out of rural and small-town Texas, and some of the population is beginning to suffer a lack of medical care comparable to that of underdeveloped countries. These articles consider the problem and present some options for improving health care delivery to rural Texans.

Delivery of Health Care↗
PubMed1989

Minute amounts of RNA are synthesized from several regions of the bacteriophage Mu DNA during the lysogenic state.

The transcription of phage Mu DNA during the lysogenic state has been quantitatively analysed. For this purpose pulse-labelled RNA from two lysogens and from their nonlysogenic parental strains were hybridized to non-overlapping Mu DNA restriction fragments covering the whole phage genome. The data revealed that all regions of the prophage are transcribed at low rates and that phage promoters are involved in this transcription. For this study an improved assay for quantitative filter hybridization was employed. The high sensitivity and reproducibility that can be obtained with the assay make it suitable for the quantitative analysis of minute amounts of mRNA.

Bacteriophage mu↗
PubMed1989

An assay for quantitative nucleic acid hybridization on membrane filters.

A quantitative nucleic acid hybridization assay based on a 6-mm-diameter nitrocellulose membrane filter and only 20 microliters of hybridization mixture per determination is described. As a consequence of the small ratio of hybridization volume to membrane surface, the hybridization rates reached in this system are higher than those obtained at volume to surface ratios of conventional protocols, allowing even RNA at very low concentrations to complete hybridization. This advantage, together with the high reproducibility and hybrid stability obtained with the assay, increases the ability of the filter hybridization technique to analyze quantitatively minute amounts of RNA.

Bacteriophages↗
PubMed1989

Pseudomonas aeruginosa outer membrane lipoprotein I gene: molecular cloning, sequence, and expression in Escherichia coli.

Lipoprotein I (OprI) is one of the major proteins of the outer membrane of Pseudomonas aeruginosa. Like porin protein F (OprF), it is a vaccine candidate because it antigenically cross-reacts with all serotype strains of the International Antigenic Typing Scheme. Since lipoprotein I was expressed in Escherichia coli under the control of its own promoter, we were able to isolate the gene by screening a lambda EMBL3 phage library with a mouse monoclonal antibody directed against lipoprotein I. The monocistronic OprI mRNA encodes a precursor protein of 83 amino acid residues including a signal peptide of 19 residues. The mature protein has a molecular weight of 6,950, not including bound glycerol and lipid. Although the amino acid sequences of protein I of P. aeruginosa and Braun's lipoprotein of E. coli differ considerably (only 30.1% identical amino acid residues), peptidoglycan in E. coli, are identical. Using lipoprotein I expressed in E. coli, it can now be tested whether this protein alone, without P. aeruginosa lipopolysaccharide contaminations, has a protective effect against P. aeruginosa infections.

Amino Acid Sequence↗
PubMed1988

Transcriptional mapping of the bacteriophage Mu DNA.

The transcription of temperate phage Mu throughout lytic development was analysed quantitatively by hybridization of pulse-labelled RNA to full-length Mu DNA and to plasmids that define Mu DNA segments covering the whole phage genome. The transcription rate (i.e. binding data corrected for the incorporation rate of the radioactive precursor, for the size of the DNA template, and for the number of phage genomes present in the bacterium at the time of analysis) revealed three defined phases of Mu transcription: early (0 to 9 min), intermediate (between 9 and the interval 14 to 17 min) and late (from the interval 14 to 17 min onward). The analysis also revealed that the region comprising the genes involved in phage morphogenesis was organized into two independent 'late' transcription units.

Bacteriophage mu↗
PubMed1987

An evaluation of visual acuity with the Corning CPF 527 lens.

The effect of visual acuity on the Corning 527 photochromatic lens was studied for a group of 50 normal patients and 53 low vision patients. Visual acuity was measured at 10 feet using three Lighthouse Low Vision Distance Acuity Charts, whose letters were randomly arranged. Acuity measurements were performed under three conditions: through a plano lens, a Corning 527 lens and an equivalent neutral density filter, each placed over the best corrective lenses. No statistically significant difference in acuity measurements were found between these three conditions.

Absorption↗
PubMed1984

A comparison of the Cavitron Biotronics tonometer to the Goldmann tonometer.

The Cavitron Biotronics tonometer operates on a principle similar to the Mackay-Marg tonometer by applanating the cornea with a probe and a 1.5 mm plunger. Measurements made with the Mackay-Marg tonometer have been shown to correlate with measurements made by other tonometers, but there are no reports of the validity or reliability of the Cavitron Biotronics tonometer. In this study, comparisons were made between intraocular pressure measurements obtained with the Cavitron Biotronics tonometer and the Goldmann tonometer. In addition, the test-retest reliability of the Cavitron Biotronics tonometer was examined.

Adult↗
PubMed1983

Lichen planus dermopathy: demonstration of a lichen planus specific epidermal antigen in affected patients.

Lichen planus is a common papulosquamous disorder of skin and mucous membranes of unknown etiology. Studies reported here demonstrate a lichen planus specific antigen (LPSA) in granular and deep prickle epithelial cells from the lichen planus lesion. Sera from seven out of eight lichen planus patients tested contained an antibody to LPSA. The LPSA was not detected in normal skin tissues from lichen planus patients, or in skin from normal donors and skin from patients with skin disorders other than lichen planus. A serologic survey of serum from people with no clinical history of lichen planus revealed approximately a 7% incidence of antibody to LPSA. These studies suggest that LPSA may be of exogenous origin.

Adolescent↗