Biomedical subjects

R Madison

Publications and source records attributed to R Madison.

At least 19 recordsLinked to original sources

PubMed1997

The process of care in preventive in-home comprehensive geriatric assessment.

OBJECTIVES: To describe the process of care of a program of in-home comprehensive geriatric assessment (CGA) and to determine: (1) if there are major findings in all domains of CGA (medical, functional, mental health, and social/ environmental), (2) if there is a continued clinical yield when CGA is repeated annually, and (3) factors that affect patient adherence with recommendations from CGA. DESIGN: Descriptive prospective study of subjects allocated to the intervention group of a 3-year randomized trial of preventive in-home CGA. SETTING: Homes of participants living in an urban setting. PARTICIPANTS: Persons aged 75 years or older and living at home who received the intervention (N = 202 subjects, mean age 80.8 years, 70% female, 95% white, 64% living alone). INTERVENTION: Annual in-home CGA and quarterly home visits by gerontologic nurse practitioners for 3 years. MEASUREMENTS: Detailed data were collected prospectively on clinical problems detected by CGA, and specific recommendations were made for these problems using an instrument developed explicitly for this project to study the CGA process. Subject adherence with these recommendations was also recorded. RESULTS: Major problems were identified in all domains of CGA; the most common problems were medical. In the first year, 76.7% of subjects had at least one major problem identified that was either previously unknown or suboptimally treated. One-third of subjects had additional major problems identified during the second and third years. A constant number of therapeutic and preventive recommendations was made each year (11.5 per subject annually). Subject adherence varied by type of recommendation (ANOVA, F = 108.4, P < .001); adherence was better for referrals to a physician than for referrals to a non-physician professional or community service or for recommendations involving self-care activities (Scheffe's test, P < .001). CONCLUSION: In these community-dwelling older people, there was a continued yield of problems identified and recommendations made when CGA was repeated annually for 3 years, supporting the practice of repeat CGA in older people in the community. Subject adherence with recommendations from CGA varied by type of recommendation, but further work is needed to determine additional factors that affect this adherence and to determine the association between the yield of CGA (i.e., problems identified, recommendations given and adherence with these recommendations) and important clinical outcomes.

Aged↗

PubMed1990

Latex nanosphere delivery system (LNDS): novel nanometer-sized carriers of fluorescent dyes and active agents selectively target neuronal subpopulations via uptake and retrograde transport.

A wide range of latex particles are described which are capable of carrying high concentrations of fluorescent dyes, drugs, and photoactive agents selectively to subpopulations of neurons in vitro and in vivo. Particle size, charge, and concentration were all found to influence uptake into cultured neurons or retrograde transport in vivo. Chromophore loadings of greater than 14% (w/w) were obtained. Incorporation of a photoactivated dye (chlorin e6) into the polymer did not compromise the ability of the dye to produce singlet oxygen following light exposure. We refer to this unique family of latex particles as the latex nanosphere delivery system (LNDS). The LNDS will be usefull for studies of neuroanatomy and nervous system development, as well as more general areas of biomedical research where it is desirable to selectively label subpopulations of cells. The LNDS also offers a means of providing targeted delivery of drugs or photoactive agents to selected subpopulations of cells; this will allow experimentation not currently possible using any existent methodology.

Animals↗

PubMed1989

Building-related illness and antibodies to albumin conjugates of formaldehyde, toluene diisocyanate, and trimellitic anhydride.

A case of building-related health complaints was investigated with respect to the relationship among frequency of symptoms, antibodies to albumin conjugates of formaldehyde (HCHO), toluene diisocyanate (TDI), and tirmellitic anhydride (TMA), and volatile organic chemicals (VOCs). The indoor air concentrations of VOCs, HCHO, TDI, and TMA did not exceed Fed-OSHA and ACGIH permissible standards. However, HCHO concentrations ranged between 0.05 and 0.08 ppm. The reported symptoms were multiple, involving the eyes, nose, sinuses, throat, lungs, skeletomuscular system, and central nervous system. Anti-HCHO, -TDI, and -TMA isotypes were found in 12 of 14 full-time employees and were nondetectable in one part-time employee. There was a positive, but not statistically significant, correlation (r values ranged between .24 and .55) between symptoms and the geometric mean titers to conjugates. The data suggest that a synergistic immunological response to airborne chemicals may be occurring in these subjects. In conclusion, immunological monitoring of affected individuals where chemicals are suspected may prove to be useful in future investigations of building-related illness.

Adult↗

PubMed1989

Acidic fibroblast growth factor enhances peripheral nerve regeneration in vivo.

When added to a collagen-filled nerve guide, purified acidic fibroblast growth factor (aFGF) increased the number of myelinated axons that regenerated across a 5-mm nerve gap distance. In addition, a greater number of primary sensory and motor neurons extended axons through the nerve guide in animals treated with aFGF. Thus the effect of aFGF on peripheral nerve regeneration is not simply an increase in axonal branching within the nerve guide tube. This is the first highly purified growth factor since nerve growth factor that has been shown to promote nerve regeneration in vivo. This experimental model provides a convenient and quantitative means to assess the effects of putative neuronotropic factors on peripheral nerve regeneration in vivo.

Action Potentials↗

PubMed1987

Colloidal gold fluorescent microspheres: a new retrograde marker visualized by light and electron microscopy.

A new retrograde tracer, rhodamine latex microspheres, permits labeled neurons to be visualized with fluorescence light microscopy. However, their use has been limited to the light microscope. We now have developed colloidal gold fluorescent microspheres which identify retrogradely labeled neurons first by fluorescence microscopy and then by electron microscopy. This new fluorescent/EM tracer will find widespread use in the field of neuroscience to elucidate the ultrastructural integrity of neuronal networks.

Animals↗

PubMed1986

A California school nurse credential survey.

This survey determined which required competencies currently employed California school nurses rated as adequate in their basic preparation for entry into school nursing practice. A questionnaire was sent to 2,861 California school nurses; 1,534 (54%) were returned and 1,227 were used in the analysis. The questionnaire listed 24 competencies required for school nursing by the California Commission on Teacher Credentialing. Demographic factors were solicited to develop a profile of the candidates who responded. Survey results indicated most nurses believed 11 of the required competencies were met in their bachelor's degree program. Many respondents did not consider their preservice training adequate in some competencies. These results could be useful to universities that are considering establishing a certificate program for school nursing.

Adult↗

PubMed1986

Is antioxidant deficiency related to chronic obstructive pulmonary disease?

This report describes an assay with the capability of detecting antioxidant activity of plasma and of purified proteins. The method is based on the enzymatic oxidation of plasma elastase inhibitory capacity of enzyme(s) in extracts of human lysosomes in the presence of hydrogen peroxide, chloride, and magnesium ions. Using this method we measured the antioxidant activity of the plasma of 59 subjects. We detected a strong relationship between a deficiency in the antioxidant activity of plasma and the presence of a family history of lung disease (p less than 0.005), and an abnormal mean FEV1/FVC ratio (p less than 0.005).

Adult↗

PubMed1986

Pursed lips breathing training using ear oximetry.

Pursed lips breathing (PLB) training is often used in the management of patients with chronic obstructive lung disease (COLD). Previous clinical studies have demonstrated that PLB improves arterial oxygen saturation (SaO2) and CO2 removal as well as relieving dyspnea. Twelve hypoxemic subjects with stable COLD were randomly assigned to either the pursed lips (P) or control group consisting of general relaxation (R). The SaO2 was monitored via ear oximetry, and respiratory rate and tidal volume were monitored using a strain gage transducer and the minute volume was calculated. The PLB was taught by an experienced instructor using the ear oximeter as a monitoring display with a goal toward increasing SaO2. The subject was taught general relaxation (Rlx) with the aid of pleasant music. We compared PLB and Rlx treatments using an A-B-A crossover study design. In both groups, PLB significantly improved SaO2 over baseline (p less than 0.001) whereas Rlx did not. We conclude that patients can learn to increase their SaO2 by PLB using ear oximetry adjunctively.

Aged↗

PubMed1985

Unfocused laser illumination kills dye-targeted mouse neurons by selective photothermolysis.

Selective photothermolysis (SP) is a novel technique by which brief, unfocused laser pulses are selectively absorbed by, and cause selective thermal damage to, endogenously pigmented structures. The present experiments demonstrate the feasibility of using an exogenous non-fluorescent chromophore (procion blue) to effect cellular damage by SP. Dorsal root ganglia neurons in vitro were selectively labeled with procion blue and subsequently damaged by unfocused laser illumination. Progressive cellular damage was assessed by propidium iodide (PI), a fluorescent dye that leaks through damaged membranes and binds to nucleic acids. Graded scores of intracellular PI fluorescence demonstrated a highly significant difference in amount of damage between groups of experimental and control cells. Selective photothermolysis is discussed as an experimental tool for neurobiologists in particular and for general use within the biomedical field.

Animals↗

PubMed1985

An in vivo model to quantify motor and sensory peripheral nerve regeneration using bioresorbable nerve guide tubes.

An in vivo preparation is presented to study the rate and time course of motor and sensory axonal regeneration. The cut ends of a transected sciatic nerve were inserted into each end of a 5-6 mm non-toxic and bioresorbable nerve guide tube to create a 4 mm nerve gap in adult mice. Subsequently, cell bodies in the ventral spinal cord and L3-L5 dorsal root ganglia that had regenerated axons across the gap were retrogradely labeled with horseradish peroxidase (HRP). The HRP was applied 3 mm distal to the nerve guide and was accessible only to axons that had regenerated through the nerve guide. Labeled cells were counted in 40 micron serial sections at 2, 4 and 6 weeks after initial nerve transection. The results indicate a significant increase in the number of labeled motor and sensory cell bodies over time. By 6 weeks after transection, approximately two thirds as many ventral horn motor cells and one third as many dorsal root ganglion sensory cells were labeled as in control non-transected animals. These data serve as a baseline to compare differential effects of additives to the nerve guide lumen in terms of sensory and motor neuron response.

Animals↗

PubMed1985

Increased rate of peripheral nerve regeneration using bioresorbable nerve guides and a laminin-containing gel.

The sciatic nerve of adult mice was transected and proximal and distal nerve stumps were sutured into a nontoxic bioresorbable nerve guide. Nerve guide lumens were either empty or filled with a gel containing 80% laminin and additional extracellular matrix components. Two weeks later cells in the L3 through L5 dorsal root ganglia and the ventral horn of the spinal cord were retrogradely filled with horseradish peroxidase. All animals with the laminin-containing gel but none with empty nerve guides displayed labeled cells. This suggests that the laminin-containing gel significantly hastened axonal regeneration in vivo.

Absorption↗

PubMed1984

Nontoxic nerve guide tubes support neovascular growth in transected rat optic nerve.

Nontoxic, bioresorbable "nerve guide" tubes were used to bridge the transected optic nerves of adult rats. Nerve guides were fabricated as polymers of synthetic poly D,L-lactates with 2% triethyl citrate added as a plasticizer. The local environment was manipulated further by the addition of the proteins collagen, fibrinogen, and anti-Thy-1 antibody to the nerve guide lumens at the time of operation. Neovascular growth through the nerve guide lumens was quantified with the aid of a computer-controlled microscope. Neovascular growth was greater in the nerve guides to which proteins had been added, compared with initially empty nerve guides. These experiments demonstrated the effectiveness of these nerve guide tubes in supporting and directing neovascular growth in the mammalian central nervous system, and suggested that specific alterations of the local environment within the nerve guide lumen can affect the extent of neovascular growth.

Animals↗

PubMed1984

Respiratory impairment in coke oven workers: relationship to work exposure and bronchial inflammation detected by sputum cytology.

Coke oven workers are at excess risk of developing lung cancer and may be at risk for chronic obstructive lung disease (COLD). We have studied 3799 male workers to assess the relationship between the two diseases. Repeated lung function and sputum cytology tests were obtained over a 3-year period. Sputum samples were assessed using standardized methods; in addition to metaplastic and neoplastic changes, we reproducibly assessed the presence and extent of acute and chronic inflammatory changes. Spirometric flow rates (FEV1) were significantly reduced in workers most exposed to coke oven emissions, particularly in those with excessive inflammatory cells and regular metaplasia in sputum. The presence of reactive bronchial epithelial cells and metaplasia were potent predictors of an abnormal FEV1/FVC. Studies like these may offer a means to investigate the relationship between COLD and lung cancer. Such changes in sputum may identify individuals at risk of developing both diseases.

Bronchi↗

PubMed1984

Retinal ganglion cells and axons survive optic nerve transection.

The effects of optic nerve transection on optic axon and retinal cell survival was studied in C57BL/6J mice. The optic nerve was transected either intracranially or intraorbitally . Data are presented which show that an intracranial transection of the optic nerve may be achieved while maintaining the blood supply to the retina. Intraorbital optic nerve transection, however, necessitates destruction of the retinal blood supply. Cell survival in the retinal ganglion cell layer is compared for both transection methods. In addition, electron microscopic evidence is presented which indicates axonal survival in the optic nerve up to at least 90 days following intracranial transection.

Animals↗

PubMed1983

Regulation of hippocampal sympathetic ingrowth: role of afferent input.

Peripheral noradrenergic fibers from the superior cervical ganglion (SCG) appear in the hippocampal formation of the adult rat central nervous system following damage to the medial septal nucleus or its afferent fibers. The appearance of these fibers coincides with a significant and substantial increase in the concentration of norepinephrine in the dentate gyrus and in the ability of synaptosomes made from the dentate to take up [3H]norepinephrine (NE) in vitro. Up to 7 weeks following a medial septal lesion, dentate norepinephrine levels are significantly lower if the sympathetic preganglionic trunk has been sectioned at the time septal lesions are made. By contrast, the uptake of [3H]NE into dentate synaptosomes is not affected by the preganglionic section. Furthermore, if the sectioned preganglionic trunk is allowed to reinnervate the SCG, the dentate NE concentration rapidly returns to levels equivalent to dentates with intact sympathetic preganglionic trunks. In addition to the ingrowth of the sympathetic fibers, central noradrenergic fibers display a sprouting or 'pruning' response to medial septal lesions. These data show that afferent input regulates the neurotransmitter concentration during sympathetic ingrowth while retrograde influences from the target appear to regulate the density or extent of the growing fibers. The experimental findings are discussed in light of the hypothesis that the hippocampal formation is capable of producing a sympathetic growth factor following septal denervation.

Afferent Pathways↗

PubMed1983

Sprouting of noradrenergic fibers in hippocampus after medial septal lesions: contributions of the central and peripheral nervous systems.

The neuronal sprouting of noradrenergic fibers was studied in the hippocampal formation. The extent and time course of lesion-induced plasticity of both central and peripheral noradrenergic neurons was determined by assaying norepinephrine (NE) concentrations and high-affinity [3H]NE uptake in the dentate gyrus at 2 to 16 weeks after medial septal lesions. Two weeks after a medial septal lesion there was a dramatic decrease in dentate NE. During the subsequent weeks normal concentrations of dentate NE were reestablished. The recovery or increase of NE with time reflected a contribution from both central and peripheral noradrenergic systems. Although both central and peripheral noradrenergic systems contributed to this recovery, they did so in very different ways. The time course of the central noradrenergic response was slower than that of the peripheral system and the final NE concentrations were quite different for the two systems. The central adrenergic system's sprouting response apparently stabilized when normal NE concentrations were attained, whereas the ingrowth of peripheral sympathetic fibers continued to concentrations that were well above normal unoperated levels. The findings have implications in relationship to the different possible controlling mechanisms governing neuronal plasticity of the central and peripheral noradrenergic systems.

Animals↗

PubMed1983

Peripheral nerve repair with bioresorbable prosthesis.

Using the transected sciatic nerve model in adult mice, regeneration of a large bundle of axons organized into the form of a nerve with myelinated and unmyelinated axons, Schwann cells, fibroblasts, collagen, blood vessels, and connective tissue sheaths has been achieved with bioresorbable microtubular guidance channels over gaps of 5 mm in nonimmobilized animals. After 4-6 wks postoperatively, the regenerated nerve cable contains on the order of 40% as many myelinated axons as were measured in the proximal nerve stumps. With the channels used so far in this model, regenerating axons pass into the distal stump in about 3-6 wks postoperatively. The guidance channels used consist of synthetic polyesters and/or polyester composites including glycolic and lactic acid polymers, and polyesters derived from Krebs Cycle dicarboxylic acids. Inflammatory response to these materials has been minimal. Biodegradation/resorption rates can be controlled so as to be compatible with axon growth rates.

Animals↗

PubMed1982

Definition and comparability of nosocomial infection rates.

Nosocomial infection rates are frequently calculated by dividing the number of infections acquired during a month by the number of patients discharged during that month. This method does not allow for prediction of future events or comparability between locations for statistical analysis. A more appropriate rate is the number of infections divided by patient-days spent in the hospital. This rate avoids the problems associated with the commonly used method. On the basis of the rate of infections per patient-day, it is possible to test for interhospital and intrahospital differences as well as for differences over time.

California↗