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Biomedical subjects

W Richardson

Publications and source records attributed to W Richardson.

At least 55 records · Page 3Linked to original sources
PubMed1985

A gamma-ray computed tomography scanner for the quantitative measurement of bone density.

A special purpose gamma-ray computed tomography scanner has been developed for the precise measurement of bone density in the distal forearm. Details of the scanner hardware and computer analysis technique are given. Suitable phantoms have been used to test the operation of the scanner, which has been used to measure trabecular and cortical bone density with a precision better than 1%.

Biomedical Engineering↗
PubMed1985

Library collection of the psychosocial publications in consultation-liaison psychiatry.

Psychiatric oncology is a relatively new area, and few comprehensive reviews of related subject matter are available. Thus, the psychiatrists at North Carolina Memorial Hospital who provide liaison to oncology saw the need for a collection of pertinent psychiatric oncology materials that could be studied by faculty, residents, and staff. Such materials would be valuable for patient consultation, lecture preparation, and research background. Their bibliography and library system are discussed here, with a description of the methods of its compilation. The unique features are referenced materials are filed in a centrally available location (departmental library), so that readers have immediate access to them, and bibliographic entries are stored in a small computer in the library, and can be retrieved by topic, title, author. The file currently holds over 340 articles, and is continuously updated. It has been extensively utilized by professionals in this tertiary care teaching hospital as well as in programs across the state.

Bibliographies as Topic↗
PubMed1984

Induction of hepatic protein synthesis by a peptide in blood plasma of patients with sepsis and trauma.

Accelerated release of amino acids from muscle and their uptake for protein synthesis by liver and other visceral tissues are characteristic of trauma or sepsis. Experimentally, this response is induced by interleukin-1 (IL-1) generated by activated macrophages in vitro. However, IL-1 has not been demonstrated in human blood. A small 4000-dalton peptide recently isolated from plasma of patients with sepsis and trauma induces muscle proteolysis and is called "proteolysis-inducing factor" (PIF). To test whether this agent has the ability also to induce hepatic protein synthesis, a series of animal experiments and clinical observations were undertaken. The structural and secretory (acute-phase reactants) in vitro protein synthesis in livers of normal rats injected intraperitoneally with IL-1 or PIF was significantly greater than that of normal rats or those injected with Ringer's lactate (p less than 0.01). In patients with sepsis and trauma the central plasma clearance rate of amino acids, a measure of visceral (principally hepatic) amino acid uptake, was elevated and correlated with the rates of protein synthesis in incubated liver slices obtained by biopsy at operation from the same patients (p less than 0.05). Both in vivo measured central plasma clearance rate of amino acids and in vitro measured hepatic protein synthesis correlated with plasma levels of PIF in the same patients (p less than 0.01 and p less than 0.05, respectively). We conclude that since PIF, and not IL-1, is present in human plasma and both are produced by activated macrophages, PIF seems to be the stable circulating cleavage product of IL-1, which induces not only muscle proteolysis but also hepatic protein synthesis, principally in the form of acute-phase reactants during infection and other states in which inflammation is present.

Amino Acids↗
PubMed1981

Health status as a measure of need for medical care: a critique.

At the national level there has been a desire to assure that individuals have access to effective personal medical care services. Accordingly, there has been an interest in linking policies on access to care to the health needs of diverse population groups. This article critiques three measures of access linked to health status: the Use-Disability Ratio, the Symptoms-Response Ratio, and the Episode of Illness Analysis. Their utility in determining whether a given level of health-service utilization is appropriate for the optimization of health status in a population is considered. As part of this task, we review the concept of health, its measurement, and data on the relationship between changes in utilization and changes in health status. Although the Use-Disability ratio may be a useful instrument to measure access equity, it appears less suited for the purpose stated above. Elements of both the Symptoms-Response Ratio and the Episode of Illness Analysis appear better suited for this purpose. Recommendations are provided on 1) the scope of services that should be included in a comprehensive construct designed to assess access related to health status, and 2) the required research to develop such a construct.

Health↗
PubMed1980

Results of the use of autotransplantation of the intraabdominal testis using microsurgical vascular anastomosis.

This study indicates that where facilities are available, the use of autotransplantation of the intraabdominal testis with microsurgical anastomosis to vessels of the groin is an acceptable, and possibly the best, alternative to orchidectomy for the intraabdominal testis. It is certainly justifiable in the case of the bilateral intraabdominal testis but in the case of the unilateral intraabdominal testis with a normally descended and apparently normal testis in the opposite hemiscrotum, the incresed incidence of neoplasia in intraabdominal testes should be taken into account in the decision on the method of treatment.

Adolescent↗
PubMed1973

Application of the singular perturbation method to reaction kinetics.

The purpose of this paper is to show how to apply the singular perturbation method to the rate equations in reaction kinetics that involve different time scales. The Lindemann scheme has been chosen for illustration, and the steady-state and equilibrium approximations used in the Lindemann scheme are discussed.

Journal Article↗
PubMed1972

Stochastic Model of Unimolecular Reactions and the RRKM Theory.

A stochastic model of unimolecular reactions has been adopted for investigation of the validity and limitation of the RRKM theory. The error caused by the steady-state approximation for distribution of energized molecules is small, while the assumption of the internal energy equilibration of energized molecules might cause serious errors for reactions of low activation energies.

Journal Article↗
PubMedDate not supplied

Deducing molecular similarity using Voronoi binding sites.

We have devised a new measure of molecular similarity with respect to given simple partitions of space into regions. The similarity is determined by numerical integration of the difference in the optimal interaction between the two molecules and the regions over a large range of interaction parameter values. Compounds differing in empirical formula are differentiated by a single infinite region; cis/trans or ortho/meta/para isomers are distinguishable by two adjacent regions that are half-spaces; and stereoisomers require five regions. This can be viewed as a natural classification of isomers. The concept can also be applied to drug binding studies to determine which molecules may bind alike in a given biological receptor and to elucidate a necessary starting geometry when a binding site is modeled for inhibitors whose experimental binding energies are different.

Binding Sites↗
PubMedDate not supplied

A simple insulated cot for neonates.

Commercially available transport incubators are sophisticated and expensive since they are designed to provide life support for premature or critically ill neonates. In maternity hospitals with inadequate heating systems, some healthy infants have difficulty maintaining their body temperature in wards and during transfer within the hospital. These babies do not require the sophistication of commercial incubators. We describe a simple insulated cot which meets these requirements at minimal cost.

Beds↗