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Biomedical subjects

R Richard

Publications and source records attributed to R Richard.

At least 55 records · Page 3Linked to original sources
PubMed1990

Glycoprotein storage in Gaucher disease: lectin histochemistry and biochemical studies.

Lectin histochemical studies were performed on formalin-fixed, frozen, and paraffin-embedded tissue sections from 19 patients with glucosylceramide lipidosis (i.e., Gaucher disease). Eleven different lectins were used to identify the specific carbohydrate residues in the undegraded stored compounds in the cytoplasm of Gaucher cells. In all cases studied, Gaucher cells stained with Concanavalia ensiformis agglutinin, Datura stramonium agglutinin, Lens culinaris, Ricinus communis agglutinin-I, and wheat germ agglutinin. These results demonstrated common carbohydrate residues in the undegraded material stored within Gaucher cells and indicated the presence of fucosylated N-linked complex oligosaccharides, and glycans containing N-acetyllactosamine repeating sequences, as well as nonreducing terminal beta-galactosyl and sialyl residues. In order to confirm these findings using biochemical methods, livers and spleens from Gaucher patients and controls, and from a patient with Niemann-Pick disease type C (included for comparison) were digested with Pronase and the resulting glycopeptides separated by gel filtration into fractions with high and low molecular weight. In the high-molecular-weight fractions from livers of Gaucher patients, the levels of sugars corresponding to N-linked glycans, as measured by gas-liquid chromatography, were elevated over those in controls. In the high-molecular-weight fractions from spleens, the levels of the same sugars were elevated in both Gaucher and Niemann-Pick type C patients. Digestion of the glycopeptides with endo-beta-galactosidase, which specifically cleaves polylactosaminoglycans, showed the presence of material containing N-acetyllactosamine repeating units in Gaucher liver glycopeptide fractions, but not in control and Niemann-Pick type C derived glycopeptide fractions. Our histochemical and biochemical studies demonstrated that in addition to glucosylceramide, affected tissues of patients with Gaucher disease accumulate glycoproteins. This accumulation could not have been predicted on the basis of the primary enzymatic defect.

Carbohydrates↗
PubMed1989

Steady-state levels of pro-dynorphin-related end-products from the brain of the amphibian, Xenopus laevis.

Steady-state analyses of prodynorphin-derived opioid peptides were conducted on acid extracts of the brain of the frog. Xenopus laevis. Radioimmunoassays specific for dynorphin A(1-17), dynorphin A(1-8), alpha-neoendorphin and dynorphin B coupled with gel filtration chromatography and reverse phase high performance liquid chromatography were used. The major prodynorphin-related end-product detected was alpha-neoendorphin. Interestingly, Leu-enkephalin was also detected. Since the Xenopus proenkephalin precursor does not contain the Leu-enkephalin sequence, these data suggest that some of the prodynorphin-related end-products had been cleaved to yield Leu-enkephalin.

Animals↗
PubMed1986

Effects of breathing a normoxic He-O2 gas mixture on exercise tolerance and VO2 max.

The purpose of these experiments was to compare the effects of breathing air (79% N2-21% O2) and a normoxic helium oxygen gas mixture (He-O2) (79% He-21% O2) on maximal oxygen uptake (VO2 max) and work tolerance during both incremental and high-intensity constant load exercise. First, eight subjects underwent two separate short incremental cycle ergometer exercise tests until the subject could not maintain the desired power output. Second, four subjects exercised to exhaustion on two separate occasions at a constant exercise intensity (100% VO2 max). Each exercise protocol required the subject to breathe air on one test and a normoxic He-O2 mixture on an additional occasion. Data analysis revealed higher (P less than 0.05) minute ventilations, an increased time to exhaustion, and a greater VO2 max during He-O2 breathing in both exercise conditions. Small but significant (P less than 0.05) differences existed in the percent hemoglobin saturated with O2 (% SO2) at exercise demands greater than 120 W during the incremental experiment and during each minute of the constant load test with He-O2 giving the higher value. These data support the hypothesis that breathing a normoxic He-O2 gas mixture during exercise elevates VO2 max and increases exercise tolerance. Further, although it appears that breathing a He-O2 mixture results in higher %SO2 during intense exercise, the increase in arterial O2 content is small and probably does not fully account for the higher VO2 max observed under these conditions.

Adult↗
PubMed1985

Unilateral Meniere's disease: is the contralateral ear normal?

Certain investigations in patients with unilateral Meniere's disease may on occasion show abnormalities in the completely symptomless contralateral ear. These tests include transtympanic electrocochleography, the acetazolamide cochlear hydration test, vestibular aqueduct tomography, and caloric testing. Eventually these ears may well become symptomatic. Previous studies have shown that otoadmittance changes are a sensitive indicator of glycerol-induced intracochlear pressure alterations in hydropic ears, but do not occur in patients without Meniere's disease. Otoadmittance parameters were evaluated in the asymptomatic ears of 73 consecutive patients with unilateral Meniere's disease. Satisfactory traces and adequate dehydration were achieved in fifty-nine. A significant change in the maximum conductance, similar to that often seen in symptomatic hydropic ears, was found in twenty-four cases (40.7%). The presence of functional abnormalities in well over one-third of asymptomatic ears means that they cannot be used as controls in clinical research studies. Furthermore, recognition of contralateral latent hydrops at the initial otologic assessment may modify the subsequent treatment strategy.

Acoustic Impedance Tests↗
PubMed1981

Uptake of tritium-labelled biogenic amines by the prostomium of the polychaete Nereis virens (Sars) (Annelida).

The uptake of tritium-labelled 5-HT, noradrenaline, 5-hydroxytrytophan, DOPA and dopamine by the cerebral ganglion and prostomial nervous system of the polychaete Nereis virens has been examined using radioautography at the level of the light microscope. Pronounced uptake of (3)H-5HT occurred in the antennal, palpal, tegumentary and nuchal nerves as well as in ganglionic nuclei 13, 14, 15, 16, 17, 20, 24 and 25, the mid-brain neuropile, the neurosecretory neuropil and the infracerebral organ; (3)H-NA uptake was observed in small cells in the prostomial epidermis, and the infracerebral organ; (3)H-dopamine only in one of two common types of epidermal mucus cells. Prostomial muscles labelled generally with (3)H-NA and at specific sites with (3)H-5HT. These observations support the concept of an efferent serotonergic system originating in several cerebral ganglionic nuclei and serving prostomial muscle and epidermis. Evidence for an afferent adrenergic system is less substantial. The role of dopamine remains obscure.

5-Hydroxytryptophan↗
PubMedDate not supplied

The elderly patient with burns: treatment considerations.

When therapists treat elderly patients with burns, they should ask themselves several questions: Am I treating elderly patients with burns "just like other patients with burns?" Am I assessing the patient's joint mobility and strength as critically as I should? Am I ensuring that further tissue trauma is avoided by instructing the nursing staff in turning/transfer techniques? Am I routinely monitoring heart rate and blood pressure? Am I requiring repetition and practice of exercises before the patient's discharge? Is my patient safe to function in the environment to which he or she is being discharged? Most physical changes in the elderly population are attributed to the aging process but often are due to diminished movement disorders arising from poor physical fitness and disuse. The "slowdown" in the older adult may result from a lack of appropriate movement practice and failure to receive reinforcement for activity. Regardless of age, physiological challenges result in enhanced functional status. Training for a specific skill increases performance in that skill just as strength training increases strength. Practice or repetition of a task improves movement and response time for that task. Appropriate physical training programs for the elderly can (1) counterbalance age-associated declines in work capacity and physical performance; (2) maintain and improve range of motion, strength, flexibility, balance, and endurance; and (3) reduce the disability of the cardiovascular, respiratory, and musculoskeletal systems that may result in decreased risk of falls and accidents. Practice of a task and maintenance of physical fitness helps ensure a high level of motor performance and speed as a person grows older. One is never too old to exercise!

Accidental Falls↗
PubMedDate not supplied

A comparison of the Tanner and Bioplasty skin mesher systems for maximal skin graft expansion.

Maximizing wound coverage of patients with burns who have meshed autografts is a primary intervention for wound closure. This study compared the Tanner and Bioplasty skin graft meshing systems for optimal skin graft expansion. Twenty patients for skin grafting were randomly assigned to either a Tanner or Bioplasty skin mesher group. Skin expansion ratios used with the Tanner group were 1.5:1 and 3:1, while Bioplasty ratios included 2:1 and 4:1. The patients' thighs were used exclusively as donor sites, and all grafts were harvested by the same surgeon. Expanded skin ratios were compared as to the difference in percent of predicted expansion outcome compared with the actual areas of the measured skin grafts. Comparing the differences of actual skin expansion with expected expansion, statistically significant results were found. When meshed skin grafts are used for wound closure, a 12.9% to 58.6% greater than anticipated area of donor skin should be harvested based on the expansion ratio selected.

Adult↗
PubMedDate not supplied

The effect of mechanical compression on chronic hand edema after burn injury: a preliminary report.

Chronic hand edema after wound healing is a troublesome condition to treat in patients with burns. Stagnant edema can cause fibrosis, which impedes rehabilitation and may lead to deformity. Although favorable results have been reported with mechanical compression used in acute injuries, no literature was found on the effects of compression for the treatment of chronic hand-burn edema. Five male patients with nine chronically edematous burned hands were subject to mechanical compression at 55 mm Hg pressure. A single-cell unit was used for a 30-minute treatment at 4:1 treatment ratio. Goniometric and volumetric hand measurements were recorded both before and after treatment. Although patients expressed a subjective feeling of improvement, no statistical difference was found in finger joint range of motion nor in hand volume when comparing pretreatment and posttreatment measurements. Many different treatment protocols exist in the literature and are discussed.

Adult↗
PubMedDate not supplied

Photographic measurement of volar forearm skin movement with wrist extension: the influence of elbow position.

An important function of skin is to allow joint range of motion to occur. An assumed clinical relationship exists between joint movement and skin pliability. The purpose of this research was to document skin movement of the forearm and wrist with photography, to quantify the amount of skin movement during wrist extension, and to investigate the influence of elbow positions on forearm skin movement. Twenty volunteers had markings placed on the skin of the volar forearm. Each subject performed the motion of wrist extension in two elbow test positions of flexion and extension. Photographs were taken of the skin markings at the beginning and end of wrist extension. A significant difference was found in the amount of forearm skin movement that occurred when the elbow was extended and flexed (p < 0.001). These results substantiate the use of multijoint range of motion during burn rehabilitation.

Adult↗