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Biomedical subjects

J Saunders

Publications and source records attributed to J Saunders.

At least 73 records · Page 4Linked to original sources
PubMed1995

Use of the teleost saccule to identify genes involved in inner ear function.

The vertebrate inner ear sensory epithelia contain different types of hair cells and supporting cells. The teleost saccule is anatomically similar to the mammalian saccule and is primarily involved in the detection of translational acceleration and orientation with respect to gravity. To facilitate molecular studies of the teleost saccule cDNA libraries were constructed from microdissected Lepomis macrochirus (bluegill sunfish) saccular maculae. To our knowledge, this is the first report of cDNA libraries constructed from the saccule. In one instance, a non-polymerase chain reaction-based method of amplifying a mRNA population from limited amounts of starting tissue was employed that allowed construction of cDNA libraries from nanogram amounts of tissue mRNA. Conventional cDNA libraries were constructed from the sunfish saccular maculae as well. These cDNA libraries enriched in hair cell and supporting cell transcripts should facilitate molecular biological studies of inner ear sensory epithelia. As an example of their utility, efforts to identify tyrosine kinases expressed in the saccular endorgan using low-stringency hybridization screening of these cDNA libraries and the partial sequence of a cDNA found to encode an erbB-2-related tyrosine kinase are also reported.

Amino Acid Sequence↗
PubMed1994

The development of a massage service for cancer patients.

Despite major technological advances in the treatment of cancer, many patients are dissatisfied with conventional biomedical interventions. This is largely because they fail to resolve long term intractable problems such as chronic pain or stress. More emphasis is now being placed on quality of life. This shift in attitude has opened the door for complementary therapies as adjuvants to traditional models of cancer care. Changes within the NHS have facilitated this transition, by the creation of the 'internal market' and the development of central funding to individual clinical directorates. To exploit these opportunities, complementary, therapists must develop new skills and be prepared to adopt NHS standards of assessment to evaluate the efficacy of their work. Standards are a component of 'Quality assurance'. They are observable, achievable and measurable, and contribute towards an acceptable evaluation process. Standards are used by health care purchasers to assess which therapies should be made available to patients within the NHS. This paper describes the development of a massage service that has been integrated into the Hammersmith Oncology Department. The massage standard is seen to be fundamental and essential to the continued development and evaluation of the project.

Ancillary Services, Hospital↗
PubMed1994

Enhancement of microbiological safety levels of aseptically admixed total parenteral nutrition solutions through low-dose gamma irradiation.

This study was undertaken to determine the effect of low-dose gamma irradiation on aseptically admixed total parenteral nutrition (TPN) solutions to which large inocula of three test bacterial species were added. Microbiological safety levels were quantified in terms of sterility assurance levels (SALs), indicating the probability of contamination occurring expressed as 10-n. The radiation sensitivity (D10 values) of test bacteria in TPN solutions inoculated with a series of bacteria recognized as common contaminants of these products, was determined. Attainable SALs of TPN solutions containing test bacteria were subsequently calculated from the D10 values. Results showed that a minimum absorbed radiation dose as low as 1.5 kGy improved the SAL of aseptically prepared TPN solutions from a probability value of 10(-3) to a value of less than 10(-8) for the microorganisms investigated. At an absorbed dose as high as 8.3 kGy, no measurable changes in amino acid, electrolyte, glucose and lipid components of the solutions were detected. These findings have important implications for the enhancement of microbiological safety levels of aseptically prepared intravenous fluids in general.

Amino Acids↗
PubMed1993

A series of penicillin derived C2-symmetric inhibitors of HIV-1 proteinase: synthesis, mode of interaction, and structure-activity relationships.

The C2-symmetric diester 1 was identified by random screening as a novel inhibitor of HIV-1 proteinase. This led to the preparation of a series of related more potent amides from readily accessible penicillins. Many of the compounds showed potent antiviral activity in HIV-1-infected MT-4 cells and an ability to inhibit syncytia formation in infected C8166 cells, with no evidence of cytotoxicity. The compounds showed no activity against other aspartyl proteinases (renin, pepsin, and cathepsin D). Structure-activity relationships support a symmetrical interaction with the enzyme. Pharmacokinetic evaluation of the ethylamide 3 revealed it was subject to rapid plasma clearance and had low oral bioavailability.

Amino Acid Sequence↗
PubMed1993

Myeloid leukaemia and osteosarcoma in CBA/H mice given 224Ra.

Four groups of 400 12-week-old CBA/H mice were injected i.p. with 69, 139, 280 and 550 Bqg-1 224Ra. A further group of 400 mice were injected i.p. with diluting solution only. The mice were then allowed unrestricted access to food and water until they died or were killed. 53 cases of myeloid leukaemia and 22 cases of osteosarcoma were confirmed in the 2000 mice injected, and for both tumour types direct relationships were shown to exist between the amount of 224Ra administered and the incidence of tumours. It is concluded that mouse is at a greater risk from myeloid leukaemia than from osteosarcoma in the region of administered 224Ra below that which causes a maximum yield of osteosarcoma. These results are discussed in the light of the present acceptance of osteosarcoma as the major risk to man from bone-seeking alpha-particle emitters.

Animals↗
PubMed1993

Prescribing for presbyopes who use VDUs.

It has been widely assumed that VDU users position their paperwork closer than the screen to their eyes by an amount which may exceed their depth of field. The design and prescription of spectacles for the presbyopic VDU user must take these working distances into account. From theoretical considerations, the focal characteristics of occupational spectacles are matched to combinations of working distances. Measurement of these distances was carried out on a sample of 243 VDU users, 101 of whom were presbyopic and 53 nearing presbyopia. The results were analysed in terms of type of work and accommodative reserve, and compared with previous studies. Contrary to the views of several previous workers, it was found that paperwork did not tend to be positioned closer than the screen to the eyes. This finding was little affected by the type of VDU use or the accommodative reserve of the subject. Special occupational spectacle lens forms are thus not generally indicated for presbyopes at the VDU workstation.

Accommodation, Ocular↗
PubMed1993

Immunohistological detection of C5b-9 complement complexes in normal and pathological human livers.

The immunohistological localization of components and neoantigens of the C5b-9 human terminal complement complex was studied in 30 human liver biopsies. C5b-9, apparently in the soluble SC5b-9 form, was invariably detected in normal liver capsule and normal portal tract connective tissue. In livers with fibrosis and or cirrhosis, the pathological connective tissue contained variable amounts of SC5b-9 which was distributed in a similar way to that seen in normal livers. There was no significant C5b-9 deposition outside of the portal tract and capsule in any of the liver biopsies. In particular, in pathological livers, there was no deposition in relation to cellular infiltrates or areas of hepatic necrosis. These data support the concept that C5b-9 is a common component of connective tissue but do not indicate that C5b-9 mediated pathways are involved in the pathogenesis of hepatic injury.

Clusterin↗
PubMed1992

L-687,306: a functionally selective and potent muscarinic M1 receptor agonist.

The oxadiazole L-687,306 is a high affinity muscarinic agonist with a N-methylscopolamine/oxotremorine-M binding profile predictive of a partial agonist. L-687,306 showed marked selectivity in functional pharmacological assays. L-687,306 was a partial agonist at muscarinic M1 receptors in the rat ganglion but a high affinity competitive antagonist at guinea-pig cardiac M2 and ileal M3 muscarinic receptors. This compound gives an opportunity to study receptor reserve involved in muscarinic receptors in vitro and in vivo.

Animals↗
PubMed1992

Novel 5-HT3 antagonists: indol-3-ylspiro(azabicycloalkane-3,5'(4'H)-oxazoles).

The synthesis and biochemical evaluation of a series of spirofused indole oxazoline 5-HT3 antagonists is described in which the oxazoline ring acts as a bioisosteric replacement for esters and amides. The effect of substitution about the indole ring has shown the steric limitations of the aromatic binding site. Incorporation of a variety of azabicyclic systems within the rigid spirofused framework has allowed the definition of a binding model which incorporates a number of known antagonists and agonists. In this model steric constraints limit substitution around the indole ring although there is some bulk tolerance at the 1- and 2-positions. The importance of constraining the basic nitrogen within an azabicyclic system is underlined by comparison with the monocyclic piperidine. The highest affinity was observed for those compounds in which the basic nitrogen occupies a bridgehead position, the most potent analogue in this group being the azabicyclic [3.3.1] system (pIC50 = 8.95), suggesting lipophilic interactions may play a role in increasing affinity. A suggested model for agonist binding is included in which the basic nitrogens are superimposed and the 5-hydroxyl group of 5-HT is superimposed on the H-bond-accepting atom of the heterocyclic linking group.

Animals↗