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Biomedical subjects

E Howe

Publications and source records attributed to E Howe.

17 recordsLinked to original sources

A comparison of protocols for the optimisation of detection of bacteria using a surface acoustic wave (SAW) biosensor.

A dual channel surface acoustic wave (SAW) device has been used as a biosensor to detect two different microorganisms, Legionella and Escherichia coli, simultaneously. A series of experiments was conducted to optimise the use of the SAW for bacterial detection using a novel protocol of coating bacteria on the sensor surface prior to addition of the antibody. Results were compared with an experiment in which a conventional protocol was utilised, where antibody was coated on the sensor surface prior to exposure to bacteria. The concentration of bacteria that attached to the surface of the SAW device was related to the antibody that specifically bound to it and therefore to frequency in a dose dependent fashion. Unlike conventional microbiological techniques quantitative results can be obtained for Legionella and E. coli down to 10(6) cells per ml within 3 h. In addition E. coli was detected down to 10(5) cells per ml in a modified protocol using sheep IgG as a blocking agent.

Bacteria↗

Differential processing of neuropeptides influences Drosophila heart rate.

Peptides that play critical physiological roles are often encoded in precursors that contain several structurally-related gene products. Differential processing of a precursor by cell-specific processing enzymes can yield multiple messengers with diverse distributions and activities. We have reported the isolation of SDNFMRFamide, DPKQDFMRFamide, and TPAEDFMRFamide from adult Drosophila melanogaster. The peptides are encoded in the FMRFamide gene and have a common C-terminal FMRFamide but different N-terminal extensions. In order to investigate the processing of the FMRFamide polypeptide protein precursor, we generated antisera to distinguish among the structurally-related neuropeptides. Utilizing a triple-label immunofluorescent protocol, we mapped the distribution of the peptides. Each peptide has a unique, non-overlapping cellular expression pattern in neural tissue suggesting that the precursor is differentially processed. In order to identify a biological activity of the peptides, we established an in vivo heart rate assay. SDNFMRFamide decreases heart rate but DPKQDFMRFamide and TPAEDFMRFamide do not, indicating that the N-terminal residues are critical for this activity. SDNFMRFamide immunoreactivity is present in the aorta, implying that SDNFMRFamide acts locally to affect heart rate; DPKQDFMRFamide and TPAEDFMRFamide antisera do not stain cardiac tissue. Our data support the conclusion that Drosophila contains cell-specific proteolytic enzymes to differentially process a polypeptide protein precursor resulting in unique expression patterns of structurally-related, yet functionally distinct neuropeptides.

Analysis of Variance↗

Isolation and amino acid sequence of a new long-chain neurotoxin with two chromatographic isoforms (Aa el and Ae e2) from the venom of the Australian death adder (Acanthophis antarcticus).

The amino acid sequence of a previously undescribed toxin from Australian death adder venom (Acanthophis antarcticus) has been elucidated. It appears to exist in two forms which are separated by reverse-phase high-performance liquid chromatography, but which have the same sequence and mol. wt. It has 79 amino acid residues and is therefore longer than other long postsynaptic neurotoxins. It shows homology with the conserved regions of the other long postsynaptic neurotoxins except for three unique substitutions of conserved residues, which are Arg-29 instead of Trp or Phe, Leu-33 instead of Arg and Thr-43 instead of Ala.

Amino Acid Sequence↗

Developing an immunisation protocol for the primary health care team.

Health visitors based at the Ely Bridge fundholding practice in Cardiff were concerned about the low uptake in child immunisations. The health visitor team describe how they developed a joint immunisation protocol in collaboration with primary health care team colleagues to enable improved uptake in line with the Health of the Nation and GP contract targets.

Child, Preschool↗

A model to evaluate whether a community can support a physician.

A major concern to the rural citizens of the United States is the availability of health care in their community. Community leaders and physicians considering locating in rural communities need a method by which they can evaluate a community's potential for supporting a physician. A detailed survey was conducted in 1986 of 25 physicians' practices in rural Oklahoma. Data were collected from the physicians on their number of patient visits and practice costs in 1985. Using this information, the authors designed a model to project the economic feasibility of establishing a physician practice in a specific community. This model can be used to project the number of physician visits a community can generate, the costs to establish and maintain a clinic, and the gross and net income of the practice.

Adolescent↗

Estimation of thyroid gland activity in the Snell dwarf mouse by ultrastructural observation of the thyroid gland, measurement of plasma thyroxine concentration and thyroid hormone binding capacity.

An ultrastructural study of the thyroid gland of the Snell dwarf mouse showed cellular activity to be very low. Follicle cell diameters were significantly lower than in controls whilst the nucleocytoplasmic ratio was significantly higher. The observed cellular activity of the thyroid cells was associated with circulating levels of thyroxine which were found to be significantly lower than in controls. Measurement of the free thyroxine index showed very little free hormone available for tissue uptake. No differences in thyroid function due to age or sex in the dwarf mice were seen. Possible endocrine imbalances contributing to the low thyroid activity in the Snell dwarf mouse are discussed.

Animals↗

Isolation of cardiac myofibrils and myosin light chains with in vivo levels of light chain phosphorylation.

Conditions are described for the preparation of functional myofibrils and myosin light chains from freeze-clamped beating hearts with the state of light chain phosphorylation chemically 'frozen' during the extraction procedure. Myofibrils were shown to be functionally intact by measurement of Ca2+ binding and ATPase activity. Highly purified cardiac myosin light chains could be routinely isolated from myofibrillar preparations using ethanol fractionation together with ion-exchange chromatography. Analysis of light chains for covalent phosphate indicated that basal levels of phosphorylation of the 18--20 000 dalton light chain of myosin in rabbit hearts beating in situ or in a perfusion apparatus were 0.3--0.4 mol/mol. Covalent phosphate content of the light chain fraction did not change during perfusion of hearts with 10 microM epinephrine.

Animals↗