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Biomedical subjects

A Johnson

Publications and source records attributed to A Johnson.

773 records · Page 43Linked to original sources
PubMedDate not supplied

Nursing care of oncology patients receiving chemotherapy.

As part of a research effort directed at identifying specific nursing activities related to the subsequent health status of the patient, this study explored relationships between selected nursing activities and patient outcomes for the oncology patient who was receiving chemotherapy. The study was correlational in design and descriptive in nature. Included in the study were 57 subjects from oncology and/or medical units in public and private nonprofit general hospitals. Human subjects' clearance was obtained for the study in each participating hospital. Data were collected primarily by means of patient and nurse responses to self-administered questionnaires. In the initial phase of data analysis, zero-order correlations were obtained for each pair of nursing activity and patient outcome variables. In addition, to identify relative contributions of different nursing activities to the health status of patients, regression analyses were performed in selected situations. The content and the quality of the explanation of the treatment and care regime were observed to be correlated positively with the patient's self-esteem. The quality of the explanation was observed to be positively related to the patient's knowledge base. Involving the patient in his care plan and giving him control over the activities of the day were positively correlated with importance of having things explained to him.

Adolescent↗
PubMedDate not supplied

Effects of TMB-8, a putative calcium antagonist, on neuromuscular transmission and muscle contractility in the mouse phrenic nerve-hemidiaphragm preparation.

The effects of TMB-8 [8-(N.N.-diethylamino)octyl-3,4,5-trimethoxybenzoate], a putative calcium antagonist, on directly and indirectly evoked isometric twitches, tetanic contractions and potassium- and caffeine-induced contractures, were investigated in the mouse isolated phrenic nerve-hemidiaphragm preparation. In the lowest concentration tested (10(-6) M), TMB-8 produced an augmentation of both directly and indirectly induced twitches. In higher concentrations (10(-5)-3 x 10(-5) M), this augmentation was followed by twitch reduction. In the highest concentrations (10(-4) M-3 x 10(-4) M), only twitch reduction in a concentration-dependent manner was observed. TMB-8 also depressed both directly and indirectly induced tetanic contractions. However, the drug was more effective in depressing neurotransmission than in reducing muscle contractility. Elevated Ca2+ (4-8 mM) or 3,4-diaminopyridine (10(-4) M) produced a good reversal of neuromuscular blockade but this effect was transient. Pretreatment with 4 mM Ca2+ had no significant effect on the time required to produce a 50% or a 90% inhibition of directly or indirectly induced twitches. However, 8 mM Ca2+ significantly prolonged the inhibitory effects of TMB-8 on indirectly, but not directly induced twitches. On the other hand, neostigmine (3 microM) appeared to hasten the blockade of transmission. Submaximal potassium-induced contractures were markedly depressed while caffeine-induced contractures were only slightly depressed by TMB-8 in the concentration range tested (10(-5)-3 x 10(-4) M). The results are consistent with the hypothesis that TMB-8 inhibits skeletal muscle contractility by a reduction in transmembrane Ca2+ movement, a depression of postsynaptic acetylcholine receptor sensitivity, and a decreased mobilization of sequestered calcium from the sarcoplasmic reticulum.

Animals↗
PubMedDate not supplied

Air-bubble entrapment as affected by investment technique, pattern angle, and use of a surface tension-reduction agent.

The effect of five dental investing techniques, three angles formed between adjoining internal pattern surfaces, and the use of a surface tension-reducing agent on air-bubble entrapment during investing were assessed. One investing technique, which mechanically mixed the investment under vacuum, invested the pattern without vacuum, then subjected the setting investment to .275 mPa of air pressure, was found to produce significantly fewer air bubbles than the other four techniques (P = 0.0096, Student's t test). The volume of the air bubbles was not found to be significantly affected by the different investing techniques, but the angle between adjoining internal pattern surfaces indicated that the more acute the angle, the larger the volume of the trapped air bubbles. When a surface tension reducer was used on the surface of patterns, pattern angles of 90 degrees had fewer trapped air bubbles than those produced with more acute tooth preparation angles, but the surface tension reducer agent had no significant effect on bubble volume. The use of a surface tension-reducing agent on the pattern surface prior to investing significantly reduced air bubble numbers (P = .054).

Air↗
PubMedDate not supplied

Studies on the muscle-paralyzing components of the juice of the banana plant.

The stem juice of the banana plant (Musa species) has been used as an arrow poison by African tribesmen. Lyophilized, partially purified extracts of the juice augment and then block both directly and indirectly evoked contractions of the mouse diaphragm. We have isolated, purified and determined the chemical composition of the active ingredients, and characterized their pharmacological activity. The lyophilized sample was extracted with a methanol-water (MeOH-H2O) (50/50) mixture and vacuum filtered. The filtrate was rotary evaporated and crystallized in a MeOH-H2O mixture to yield potassium nitrate crystals (melting point 332-334 degrees C). The filtrate was concentrated and chromatographed over Sephadex LH-20 gel using MeOH-H2O (40/60) as the eluent. The active component was found to be magnesium nitrate crystals (melting point 87-89 degrees C). In the mouse isolated phrenic nerve-hemidiaphragm preparation, the pharmacological profile of the first component was similar to that for authentic potassium nitrate which augments in low concentrations, and in higher concentrations augments, and then blocks both directly evoked muscle contraction the neuromuscular transmission. The second component had a profile of activity similar to that for authentic magnesium nitrate which only blocks neuromuscular transmission. It can be concluded that the two major active principles in the banana stem juice are potassium nitrate and magnesium nitrate.

Animals↗
PubMedDate not supplied

The evaluation of factors affecting the castability of metal ceramic alloy--investment combinations.

An evaluation of the castability of metal ceramic alloy-investment combinations using a mesh test and utilizing a factorial design concept has shown that different metal ceramic alloys (gold-based, palladium-based, and nickel-chromium-based alloys) react differently, as far as castability is concerned, to various factors involved in the casting process. These factors were divided into two groups: procedural factors, that included sprue diameter, investing technique, and melting and casting method; and operator factors, which included alloy casting temperature, mould temperature, and heat-soak times. Each of these factors had two or three levels.

Chromium Alloys↗
PubMedDate not supplied

Staff attitudes toward parent participation in the care of children who are hospitalized.

A nonrandom sample of 62 staff who care for children on four pediatric wards at an urban women's and children's hospital in South Australia participated in a study to identify staff attitudes toward parents participating in the care of their child in the hospital and the personal and professional characteristics that may influence these attitudes. Participants completed two questionnaires, which included the Parent Participation Attitude Scale (PPAS) and a Personal and Professional Characteristics Data questionnaire. Analysis of variance indicated that the majority of staff had a neutral attitude (PPAS score M = 72; 61-84 = neutral range) toward parents participating in their hospitalized child's care. Staff members who were registered nurses, parents, married, or associated with the burns, craniofacial, and general surgery ward or the infectious diseases ward had more positive attitudes toward parent participation than did other staff members who did not possess these characteristics. The main difference in attitude related to professional characteristics: registered nurses scored a higher mean score reflecting a more accepting attitude than any other professional group participating in the study. The results provided direction to support attitudinal and practice change focused on developing a collaborative model of care in which nurse, children, and parents work together in partnership.

Adult↗
PubMedDate not supplied

Hemodialysis patient management by telemedicine: design and implementation.

The authors describe the design and implementation of a personal computer based telemedicine system for managing patients by telemedicine. With three identical systems connected by high speed T1 lines, the physician (or allied healthcare giver) can interact, by videoconferencing, and by using multimedia files, with patients at two remote hemodialysis sites. The physician is able to visualize specifically the patient's fistula/graft, and auscultate fistula, heart and lung sounds, and incorporate still pictures or audio sounds in the patient's multimedia database folder, which also contains an electronic and paperless medical record. In addition there is the capability of downloading into this database all the machine parameters during dialysis.

Databases, Factual↗