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Biomedical subjects

F Ferguson

Publications and source records attributed to F Ferguson.

At least 19 recordsLinked to original sources
PubMed2001

Racial and ethnic differences in drug treatment entry of injection drug users in Massachusetts.

This article examines patterns of drug treatment entry among 28,000 adult injection drug users (IDUs), with special attention to racial and ethnic differences. The data analyzed originates from a statewide drug-treatment database covering four years. Through the use of logistic regression analysis, the study identified significant population differences between those who used detoxification only, those who used residential treatment and those who used methadone maintenance. Latino IDUs were approximately a third less likely than Caucasian IDUs to enter residential treatment and African American IDUs were half as likely as Caucasian IDUs to enter methadone maintenance treatment. This article discusses specific programmatic and research implications including the need to determine whether differential entry rates are due to access, client awareness, cultural, referral or other factors.

Adult↗
PubMed1995

Cosmic dust analog simulation in a microgravity environment: the STARDUST program.

We have undertaken a project called STARDUST which is a collaboration with Italian and American investigators. The goals of this program are to study the condensation and coagulation of refractory materials from the vapor and to study the properties of the resulting grains as analogs to cosmic dust particles. To reduce thermal convective currents and to develop valuable experience in designing an experiment for the Gas-Grain Simulation Facility aboard Space Station Freedom we have built and flown a new chamber to study these processes under periods of microgravity available on NASA's KC-135 Research Aircraft. Preliminary results from flights with magnesium and zinc are discussed.

Cosmic Dust↗
PubMed1993

The effects of group housing on the research use of the laboratory rabbit.

This project evaluated the influence of group housing on common aspects of research use of female laboratory rabbits (Oryctolagus cuniculus). Eight rabbits housed individually in conventional cages were compared to a second group of 8 housed as a social group in a proportionately larger enclosure. The group housing method provided increased opportunities for exercise, social contact, and a more novel environment. As a function of housing style, the 2 experimental groups were compared on humoral and delayed hypersensitivity response, feed intake, growth rate, and selected physiological parameters that are considered to reflect stress in most species. Single and group housed rabbits did not significantly differ in physiological and immunological measurements, indicating that the practical research performance (immune response, stress level, growth rates etc.) of these rabbits was not significantly affected by group housing compared with the more traditional single housing. Analysis of group social behaviour indicated that the rabbits preferred small social groups, had preferences for microenvironments within the enclosure, and exhibited behaviours that are not possible when housed singly. Group housing appeared to be a successful method for enriching the environment of female rabbits and aspects of it should be considered in the approach to housing rabbits used in research.

Animals↗
PubMed1991

Age-related changes in release of soluble interleukin-2 receptor by murine lymphocytes.

The purpose of this study was to investigate whether the presence of soluble interleukin-2 receptors (sIL-2R) in the supernatants of activated splenocytes correlates with age progression in C57BL/6 mice. In addition, the relationship between IL-2R cell surface expression and release of sIL-2R was examined. The results indicated splenocytes from young (3-4-month-old) mice release higher levels of sIL-2R than those from intermediate (18-19-month-old) or old (24-25-month-old) mice. While there was no statistical difference between sIL-2R levels in intermediate and old mice in this study, the old mice did have a slightly higher release of sIL-2R than the intermediate mice. There was a correlation between IL-2R cell surface expression and the level of sIL-2R in the young and the intermediate age groups. In old mice there was no correlation between these two parameters.

Aging↗
PubMed1988

Characteristics of Yorkshire swine natural killer cells.

The present study examined the properties of NK activity in Yorkshire swine. The results support other porcine studies which indicate the swine NK system has both similarities and differences to this system in other species. Profiles of NK activity indicated swine NK cells are highly reactive against the YAC-1 lymphoma, the K-562 myeloid leukemia, the P-815 mastocytoma, and the TU-5 virally transformed fibroblast. In contrast, the MOLT-4 and SB leukemias are NK resistant. Kinetic studies indicated that in Yorkshire swine, NK lysis begins 6 h after mixing effectors and targets. The kinetics of the lytic reaction differ both from other breeds of swine and from other species, where cytotoxicity is readily measured in 4-h assays. The delayed lysis was not due to delayed target cell recognition, because Yorkshire swine NK cells are rapidly bound to tumor targets. The delayed lysis seems to be due to a refractoriness in the NK lytic mechanism. This delay may relate to the morphologic finding that the target-binding cell in Yorkshire swine appeared quite different from the large granular lymphocyte (LGL) reported as the NK effector in humans and rodents. Indeed, in light microscopic studies the typical tumor-binding cell in Yorkshire swine is a small, apparently nongranular, lymphocyte. Analysis of NK activity at the single cell level was performed with single effector-tumor conjugates immobilized in agarose. Generally, lysis by target binders paralleled sensitivity to lysis in 51Cr release tests, indicating lysis in agarose may be used as an NK index in swine. Like other species, swine NK cells were found to be nonadherent lymphocytes with a characteristic tissue distribution. Peripheral blood and spleen had the highest levels of NK activity. Lymph node cells displayed a small amount of NK activity which was limited to the YAC-1 target, while thymocytes showed no appreciable NK activity against any of the cell lines tested.

Animals↗
PubMed1987

Foot care.

Explore the source record for details and available documents.

Foot Diseases↗
PubMed1985

Influence of sex differences and knee joint position on electrical stimulation-modulated strength increases.

This study examined the influence of sex differences and knee joint position on the effectiveness of isometric electrical stimulation in improving isometric and isokinetic strength. Twenty-seven females and 28 male subjects were assigned to either a control group (C) that received no electrical stimulation, to an experimental group that received stimulation of the quadriceps with the knee flexed at 65 degrees (EF), or to an experimental group that received electrical stimulation of the quadriceps with the knee fully extended (EE). Experimental subjects received 15 min of electrical stimulation 3 times/wk for a total of 6 wk. Before and after the study, knee extension strength was measured with a Cybex II, isometrically at 65 degrees of knee flexion and isokinetically at 30 degrees . s-1, 60 degrees . s-1, 90 degrees . s-1, and 120 degrees s-1. Multivariate analysis of covariance, using the pretests as the covariate, revealed no sex differences in responsiveness to electrical stimulation. EF was superior to EE at 30 degrees . s-1 and 120 degrees . s-1 in females and at 120 degrees . s-1 in males (P less than 0.05). Male and female EF was superior to C in all tests. EE was higher than C at isometric, 30 degrees . s-1, 90 degrees . s-1, and 120 degrees . s-1 in females and at isometric and 30 degrees . s-1 in males. These data suggest that electrical stimulation at the quadriceps can increase isometric and isokinetic strength and may be more effective in improving isokinetic strength if the knee is flexed during treatment.

Adult↗
PubMed1979

Making hospital preparation child-centered (with a little help from Emily).

Helping youg children learn about the hospital shoould, ideally, involve a multifaceted approach that utilizes tools appropriate to the child's age and needs. The hospital preparation process at Alberta Children's Hospital that has attempted to achieve this end through the coordinated efforts of the Recreation/Child Life and Nursing departments is discussed. Our preparation process consists of several phases, commencing prior to admission and carrying right through until discharge, with the "thread" that draws it all together being a whimsical kitten named Emily.

Alberta↗
PubMed1978

Teratology study in mice subjected to inhalation of diethylhydroxylamine, nitroethane, and diethylamine hydrogen sulfite.

Pregnant female mice were exposed from Days 6 to 17 of pregnancy to 8.9 +/- 2.0 ppm of diethylhydroxylamine and 14.3 +/- 2.0 ppm of nitroethane. Exposures were for 8.25 +/- 2.25 hours/day including weekends. The mice were also exposed continuously for 24 hours a day to the vapor of diethylamine hydrogen sulfite. The exposure produced no effect on the dams compared to the control group. There was no evidence of compound-induced terata, variation in sex ratio, embryotoxicity, or inhibition of fetal growth and development.

Administration, Inhalation↗
PubMed1977

Platelet dynamics in chronic liver disease with special reference to the role of the spleen.

In all of 12 patients with chronic liver disease, whose platelet dynamics were investigated by the 51Cr-labelling technique in association with surface counting, platelet survival was reduced and in 11 the splenic platelet pool was increased. Surface counting showed high initial spleen liver ratios in eight patients, and in four there was evidence of progressive destruction of platelets in the spleen. In one patient, subsequently shown to have a hepatoma, progressive accumulation of platelets was noted at the tumour site.

Adult↗
PubMedDate not supplied

Age-related changes in immune parameters in a very old population of Swedish people: a longitudinal study.

This study used a longitudinal design to examine age-related changes in a well-defined sample of Swedish people ranging from 86 to 92 years of age at baseline. The longitudinal design encompassed three measurement occasions with 1 year intermeasurement intervals. The results were analyzed by multivariate analyses of variance (MANOVA), which is useful for comparing individuals over time. Healthy middle-aged subjects (39 years SD +/- 5.8) served as controls. The proliferative responses to Concanavalin A (Con A), a T-cell mitogen, indicated significant lower levels in responses of the old when the two groups were compared. The MANOVA revealed no significant change in mitogen responses over measurement occasions in the old sample as compared with the young. However, when cell types and lymphocyte subpopulations were examined, significant differences were found between the two age groups in many of these parameters and for some (lymphocyte percentages and numbers, CD3 numbers) the MANOVA indicated significant decreases over the measurement occasions in the very old. The results also consistently indicated significant intraindividual correlations in cell types, lymphocyte subpopulations, and mitogen responses over time.

Adult↗
PubMedDate not supplied

An overview of the cosmic dust analogue material production in reduced gravity: the STARDUST experience.

The formation, properties and chemical dynamics of microparticles are important in a wide variety of technical and scientific fields including synthesis of semiconductor crystals from the vapour, heterogeneous chemistry in the stratosphere and the formation of cosmic dust surrounding the stars. Gravitational effects on particle formation from vapors include gas convection and buoyancy and particle sedimentation. These processes can be significantly reduced by studying condensation and agglomeration of particles in microgravity. In addition, to accurately simulate particle formation near stars, which takes place under low gravity conditions, studies in microgravity are desired. We report here the STARDUST experience, a recent collaborative effort that brings together a successful American program of microgravity experiments on particle formation aboard NASA KC-135 Reduced Gravity Research Aircraft and several Italian research groups with expertise in microgravity research and astrophysical dust formation. The program goal is to study the formation and properties of high temperature particles and gases that are of interest in astrophysics and planetary science. To do so we are developing techniques that are generally applicable to study particle formation and properties, taking advantage of the microgravity environment to allow accurate control of system parameters.

Astronomy↗