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Biomedical subjects

E James

Publications and source records attributed to E James.

124 records · Page 7Linked to original sources
PubMed1965

The mechanism of the reaction catalysed by adenosine triphosphate-creatine phosphotransferase.

1. The forward and reverse reactions catalysed by ATP-creatine phosphotransferase have been studied kinetically at pH8.0 in the presence and absence of products, under conditions in which the free Mg(2+) concentration was maintained constant at 1mm. Thus at fixed pH the reaction may be considered as being bireactant and expressed as:MgATP(2-)+creatine(0)right harpoon over left harpoonMgADP(-)+phosphocreatine(2-)2. The initial-velocity pattern in the absence of products and the product-inhibition pattern have been determined. These are consistent with a random mechanism in which all steps are in rapid equilibrium except that concerned with the interconversion of the central ternary complexes, and in which two dead-end complexes (enzyme-MgADP-creatine and enzyme-MgATP-phosphocreatine) are formed. The results are in accord with previous suggestions that the enzyme possesses distinct sites for the combination of the nucleotide and guanidino substrates. 3. Values have been determined for the Michaelis and dissociation constants involved in the combination of each substrate with various enzyme forms. Although these values cannot be regarded as absolute, they appear to indicate that the presence of one substrate on the enzyme enhances the combination of the second substrate. In addition, it would seem that in the formation of the enzyme-MgADP-creatine complex the concentration of one reactant does not affect the combination of the other. This contrasts with the formation of the enzyme-MgATP-phosphocreatine complex, where each reactant hinders the combination of the other.

Journal Article↗
PubMedDate not supplied

The effect of aging on the growth of colon cancer.

Reports on the effect of patient age on the prognosis for colon cancer vary. We have tested the effect of aging using a model of murine colon adenocarcinoma in groups of mice of different ages. In experiment A, Balb/c mice of age groups 3-4 weeks, 10-12 weeks, 24-32 weeks and 40-48 weeks (13 mice/group) were injected with 5 X 10(4) MC-26 cells subcutaneously in the right flank. Tumors were measured twice weekly, and the rate of occurrence of tumor, mortality rate, and growth rate were calculated. In experiment B, the same plan as experiment A was used, except mice of age groups I (14 days), II (3-4 weeks), and III (20-22 months) were used with tumor doses of 1 X 10(4) cells and 5 X 10(5) cells (9-15 mice/group). In both experiments, the rate of growth of tumor, mortality rate, and sizes of tumors obtained were the same. In experiment A, the rate of occurrence of the tumors was the same in all groups, but in experiment B the occurrence of the tumor varied. A palpable tumor appeared earliest in the weanling mice (14 days), next in old mice (20-22 months), and last in the young adult group (3-4 weeks). Tumor doubling time was longest in the young adult mice (7 days), intermediate in the old mice (6.1 days), and shortest in the weanling mice (5.5 days). Established tumors grew at similar rates (as assessed by doubling time), independent of host age. Mortality rates were similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMedDate not supplied

DIVSEL and COMPLIB--strategies for the design and comparison of combinatorial libraries using pharmacophoric descriptors.

Screening synthetic combinatorial libraries may facilitate rapid drug lead discovery by substantially increasing the number of molecules tested. Drug discovery efficiency and productivity can be further improved by designing libraries to maximize their molecular diversity or by comparing them to existing collections of compounds and/or libraries to select those that complement the properties already well represented. In this paper we describe two strategies to aid in the design and comparison of combinatorial libraries. The methods employ multi-pharmacophore three-dimensional (3D) descriptors in combination with two recent proposals for dissimilarity-based compound selection and library comparison. This method allows the design to be performed in product space and library comparison to consider all pair-wise intermolecular contributions to the diversity.

Drug Design↗
PubMedDate not supplied

Sex and the Church.

Explore the source record for details and available documents.

Attitude↗
PubMedDate not supplied

The relevance of degree-level preparation for community nurses.

The most recent changes in the preparation of specialist community nurses assume that educational improvements automatically increase the skills and knowledge of the participants and thus the subsequent quality of care. The rapidly changing environment of community healthcare delivery has meant that the possession of degree-level qualification is now seen as necessary for flexibility and responsiveness to change. However, the philosophy behind this thinking is flawed--education does not always reflect the reality of care delivery. Specialist community nurses can become further distant allowing them to concentrate on the practical application of their newly acquired knowledge.

Community Health Nursing↗
PubMedDate not supplied

Single-use/multiple-use gowns and drapes: criteria for decision making.

1. Perioperative managers have more product choices for gowning and draping materials than ever before. Decision making is more difficult, yet more critical. The product/system selected must meet the patient care, employee protection, and cost expectations of the department. 2. Decision-making should be based on product characteristics, cost considerations, and availability of resources in the institution or service area. 3. Before deciding on any product, a criteria-based evaluation should be conducted. Product, characteristics should be weighed in terms of importance.

Bedding and Linens↗