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Biomedical subjects

D M Powell

Publications and source records attributed to D M Powell.

52 records · Page 3Linked to original sources
PubMed1986

Induction of HTLV-III/LAV from a nonvirus-producing T-cell line: implications for latency.

When the human T-cell line A3.01 is infected with HTLV-III/LAV, the virus associated with the acquired immune deficiency syndrome (AIDS), most of the cells are killed. However, a small number of cells that lack the Leu-3 surface marker survive. Under normal conditions these surviving cells do not produce virus, nor can they be infected by the virus, but they can be induced to produce virus by treatment with 5-iodo-2'-deoxyuridine. This response can be induced for as long as 3 months after the initial infection, suggesting that the cells may harbor a latent form of HTLV-III/LAV.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Managing organizational problems in alternative service organizations.

Alternative Service Organizations--hotlines, shelters, crisis centers, etc.--are a growing and essential part of the overall human service delivery system. These organizations face predictable problems which arise from their unique history, structure, and mission. Using a political economy perspective, the common issues and professionalization, funding, and formalization are discussed and procedures for effectively managing resulting problems are suggested.

Community Health Centers↗
PubMed1982

Local and systemic toxicity resulting from large-volume ip administration of doxorubicin in the rat.

Doxorubicin was administered to rats in a simulated "belly bath" protocol. Fifty milliliters of various concentrations of drug solution was administered ip and was allowed to remain in situ for either 4 or 36 hours prior to removal. Animals were analyzed at 2, 14, and 60 days after treatment. Doses ranged from lethal (75 and 150 micrograms/ml for 4 hours; 12 and 24 micrograms/ml for 36 hours) to nontoxic (5 micrograms/ml for 4 hours). The most common lesion in surviving animals was chronic fibrosing peritonitis. Grossly, there were large volumes of peritoneal fluid in animals exposed to low concentrations (12 and 24 micrograms/ml) for 36 hours, but peritoneal adhesions were the most commonly observed finding when higher concentrations (20-150 micrograms/ml) were used for 4 hours. Commonly observed systemic toxic effects (bone marrow, gastrointestinal tract, and heart) were not seen in this study. Vehicle-treated control animals were negative for all histologic lesions and gross observations.

Animals↗
PubMed1980

Serological relationships among budding, prosthecate bacteria.

The somatic antigens of 25 strains of budding bacteria were typed and 14 serologically distinct groups were identified, suggesting considerable antigenic diversity among hyphomicrobia. Ten of the groups were represented by a single isolate, 2 contained two isolates, 1 three isolates, and 1 eight isolates. The strains in the largest group of eight isolates each shared at least one common antigen. However, there was also considerable antigenic heterogeneity within this cluster. Serological activity resided in the lipopolysaccharide (LPS) portion of cell walls and also in a heat labile component of Hyphomicrobium neptunium. The amino acid utilizing isolates, H. neptunium and Hyphomonas polymorpha, were serologically unrelated and it is suggested that the two organisms could be grouped as members of the same genus but not the same species.

Agglutination Tests↗
PubMedDate not supplied

Recovery from deep-plane rhytidectomy following unilateral wound treatment with autologous platelet gel: a pilot study.

OBJECTIVE: To determine the effects of treatment with autologous platelet-rich plasma mixed with thrombin and calcium chloride to form an autologous platelet gel (APG) on postoperative recovery from deep-plane rhytidectomy. STUDY DESIGN: A prospective, randomized, controlled pilot study. SETTING: An accredited ambulatory facial plastic surgery center. PATIENTS: Healthy volunteer women (N = 8) undergoing rhytidectomy. INTERVENTION: Unilateral autologous platelet-rich plasma wound treatment during standard deep-plane rhytidectomy. MAIN OUTCOME MEASURES: Staged postoperative facial photographs were graded in a blinded fashion by 3 facial plastic surgeon reviewers for postoperative ecchymosis and edema. Each facial side treated with APG that demonstrated less edema or ecchymosis than the non-APG-treated side was designated a positive response; otherwise, the response was equal (no difference) or negative (untreated side had less edema or ecchymosis). RESULTS: Twenty-one positive and 21 equal responses were observed compared with 8 negative ones. Of 20 unanimous observations, 15 were positive, only 3 equal, and 1 negative. CONCLUSIONS: Treatment with APG may prevent or improve edema or ecchymosis after deep-plane rhytidectomy. This trend is more apparent for ecchymosis than for edema, and is chiefly demonstrable in the early phases of recovery. These observations are consistent with previous reports of cell tissue culture and wound response to concentrated platelet product.

Blood Platelets↗
PubMedDate not supplied

Influence of knot configuration and tying technique on the mechanical performance of sutures.

The purpose of this investigation was to determine the influence of knot configuration and tying technique on the mechanical performance of surgical sutures. Multifilament and monofilament nylon sutures were selected for this evaluation because they are commonly used in wound closure. The mechanical performance of these sutures was judged by the following parameters: knot breakage force, configuration of secure knots, and knot run down force. During each test, tension was applied at either rapid or slow rates, which correlates with the physician's speed of tying knots. On the basis of these mechanical performance tests, four throw square (1 = 1 = 1 =1) knots and five throw square (1 = 1 = 1 = 1 = 1) knots are recommended for monofilament nylon and multifilament nylon sutures, respectively, in which the speed of application of forces to the knots is relatively slow. Because these tests can easily be replicated in any laboratory, manufacturers now have a scientific basis for recommending specific tying techniques for their surgical sutures.

Physical Phenomena↗
PubMedDate not supplied

Damage to tissue defenses by EMLA cream.

EMLA is a new topical agent that safely anesthetizes intact skin. The purpose of this study was to determine if this cream could be safely used for anesthetizing wounds. This investigation evaluated the potential toxicity of EMLA cream in wounds by measuring its effect on host defenses and on the biology of wound repair. In contaminated wounds, EMLA cream elicited an exaggerated inflammatory response that damaged host defenses, inviting the development of infection. As a result of these investigations, we do not recommend the use of EMLA cream in wounds.

Anesthetics, Local↗
PubMedDate not supplied

Concurrence of multiple sclerosis and Hodgkin's disease.

Although multiple sclerosis and Hodgkin's disease are reported to have similar epidemiologic features, this is only the first case report in which there was concurrence of these diseases. Fourteen years after successful treatment of Hodgkin's disease, this 31-year-old white male developed multiple sclerosis. The diagnosis of multiple sclerosis was made on the basis of clinical and paraclinical findings that were characteristic of multiple sclerosis. In addition, specific tests were performed to rule out a variety of infectious, metabolic, and neoplastic diseases that simulate multiple sclerosis.

Adult↗
PubMedDate not supplied

Adaptive communication systems for patients with mobility disorders.

An adaptive communication system has been developed for individuals with mobility disorders. It uses specialized computer software and hardware that compensate for this disability. For an individual with a motor-control impairment who is not able to use a keyboard effectively, a computer voice-recognition technology now removes this communication barrier. Speech-recognition systems consist of three basic components: speech processing, speech recognition, and speech understanding. The new Dragon Dictate (Dragon Systems, Inc., Newton, Mass.) is the first large-vocabulary speech recognition system in the personal computer industry that interactively learns a user's vocabulary and mode of speaking and responds to natural language rather than to limited sets of words. This speech-recognition system requires a microprocessor, a display monitor, a printer, and specific software packages, including word-processing and enhanced memory-management software. Important considerations in the use of this speech-recognition system include microphone positioning and training of the system. With the advent of this new voice-recognition computer system, another communication barrier between the disabled and society has been overcome.

Communication Devices for People with Disabilities↗
PubMedDate not supplied

Computer analysis of the performance of the BTE Work Simulator.

The BTE Work Simulator (Baltimore, Therapeutic Equipment Co., Hanover, Md.) recreates the work environment by providing a rotatable shaft to which a variety of tools can be attached. The patient can simulate the coordinated muscle and joint movements involved in the work situation, exercising either isometrically or isotonically, and thereby increase the potential for return to work. The BTE Work Simulator has four major components: the exercise head to provide variable resistance, tools that attach to the exercise head, a control console containing a microprocessor that calculates work and power, and the Quest software package (Baltimore Therapeutic Equipment Co.). Quest provides four static/isometric and seven dynamic/isotonic tests that can be used to document the extent of a patient's impairment. In addition, it has daily treatment options and acts as an extensive data base capable of retrieving any stored test or treatment results. This software system greatly facilitates the use of the BTE Work Simulator by providing instant calculations of power and coefficients of variation, immediate patient feedback, graphic expansion of the data, and printed evaluation reports.

Computer Simulation↗