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Biomedical subjects

C Edwards

Publications and source records attributed to C Edwards.

At least 361 records · Page 20Linked to original sources
PubMed1966

The effect of the replacement of calcium by strontium on excitation-contraction coupling in frog skeletal muscle.

1. In frog skeletal muscle strontium can replace calcium in potassium contractures for 5 hr, though it is less effective than Ca. Sr can restore the responsiveness to K after it had been lost in the presence of Mn.2. Muscles refractory to caffeine following repeated exposure to it in the absence of Ca, recover in part following addition of Sr.3. The uptake of (85)Sr was increased during mechanical activity, whereas the uptake of (58)Co was not changed. Resting uptake of (58)Co was 3-4 times greater than that of (85)Sr.4. Sr fully activated the myofibrillar adenosine triphosphatase (ATP-ase), though its affinity was about 30 times less than Ca.5. The sarcoplasmic reticulum took up Sr, though less effectively than Ca.

Adenosine Triphosphatases↗
PubMed1965

Interaction between the effects of inside and outside Na and K on bullfrog skin potential.

The composition of the solution bathing one border of the isolated frog skin affects the response of the potential across the skin to changes in the composition of the solution bathing the opposite border. Increasing the K concentration of the inside (corium) bathing solution decreased the sensitivity of the potential to a change in outside Na concentration. Decreasing the outside Na concentration decreased the sensitivity of the potential to a change in inside K concentration. Increasing the total ionic strength of the outside bathing solution or of both bathing solutions decreased the sensitivity of the potential to a change in outside Na concentration.

Animals↗
PubMedDate not supplied

Adherence to disease-modifying therapy in multiple sclerosis: Part I.

Multiple sclerosis (MS) is a chronic, debilitating disease for which there is no cure. However, the recent introduction of injectable immunomodulating agents has made it possible to reduce the frequency of relapsing episodes and to possibly slow its progression. The use of these agents is recommended by the National MS Society, however, their true potential cannot be realized if patients do not accept them and healthcare professionals do not promote them. Because MS is unpredictable, and treatments can produce side effects, ensuring adherence to the recommended therapy is a complex and challenging issue. A better understanding of the obstacles to adherence, and the identification of possible solutions, should be of value to nurses, who have numerous opportunities to encourage patients to initiate and continue therapy. This article, which is in two parts, describes the particular problems of treatment adherence, and proposes that the transtheoretical model of behavior change can be useful in achieving treatment goals in MS and in other chronic disease states. This model is based upon the concept that a patient's "readiness for change" is crucial, and that attempts at intervention should be sensitive to the patient's changing conditions and state of mind. Nurses who work with patients with MS and other chronic diseases can apply the model to help their patients accept and adhere to the demands of ongoing treatment.

Chronic Disease↗
PubMedDate not supplied

Adherence to disease-modifying therapy in multiple sclerosis: Part II.

Multiple sclerosis (MS) is a chronic, debilitating disease for which there is no cure; however, the recent introduction of injectable immunomodulating agents has reduced the rate of relapsing episodes and possibly slowed the progression of the disease. These disease-modifying agents are recommended by the National MS Society, but their true potential cannot be realized if patients do not accept them and healthcare professionals do not promote them. Since MS has an unpredictable course, and treatments can produce side effects, adherence to the recommended therapy is a complex and challenging issue. Improved understanding of the obstacles to adherence and the identification of possible solutions should be of value to nurses, who have numerous opportunities to encourage patients to initiate and continue therapy. Part I of this article, published in the September/October 2001 issue of Rehabilitation Nursing, described the particular problems of treatment adherence in MS. Part II proposes that the transtheoretical model of behavior change can be a useful tool in achieving both patient acceptance and treatment goals. This model is founded upon the concept that readiness for change is crucial, and that attempts at intervention should be sensitive to the patients' changing conditions and states of mind.

Humans↗
PubMedDate not supplied

Evaluation of biomechanical properties of human skin.

Measurement of the physical properties of skin may seem "esoteric" and of little relevance to clinical science; however, the noninvasive nature of available techniques provides unique opportunities for monitoring the effects of disease, drugs, or cosmetics over time on exactly the same area of skin. In vitro testing gives repeatable standardized methods that can supply basic elastic and viscoelastic moduli for skin, which for low strain are comparable to results obtained from in vivo tests. Interpretation of in vivo tests can be difficult, as no analytical model has been developed that can relate measurements from these tests directly to basic skin properties. Each method and each implementation of that method has subtle differences from every other method so that results between studies are difficult to compare; however, the alternative to the bioengineering tests is the hand and eye, which provide subjective (and often biased), nonlinear, and notoriously variable data between individuals. Judging the severity of involvement, the changes due to treatment or progress of disease, and the efficacy of competing treatments is very difficult, even for an experienced clinician. Objective, numerical information on the effects of different active compounds and their formulations is essential if new preparations are to be optimized. Measurement of mechanical properties is one aspect of this important field of endeavor.

Biomechanical Phenomena↗
PubMedDate not supplied

Synthesis and biological studies of 5-aminolevulinic acid-containing dendrimers for photodynamic therapy.

Using a convergent growth approach, a series of novel 5-aminolevulinic acid (ALA)-containing dendrimers have been synthesized. In these molecules, ALA residues are attached to the periphery by ester linkages, with amide bonds connecting the dendrons. Three first-generation dendrimers, bearing either 6 or 9 ALA residues, were synthesized by attachment of a tris(Boc-protected ALA)-containing wedge (1) to a di- or tripodent aromatic, or tripodent aliphatic core. Two second generation 18-ALA-containing dendrimers were also synthesized using a 3,3'-iminodipropionic acid spacer unit between wedge 1 and the aromatic core. These compounds differed only in the distance between the core and the linker unit. The Boc-protected dendrimers were deprotected using trifluoroacetic acid and isolated as their TFA salts. The potential of these ALA ester dendrimers as macromolecular prodrugs for photodynamic therapy has been demonstrated in the tumorigenic keratinocyte PAM 212 cell line.

Aminolevulinic Acid↗
PubMedDate not supplied

Uterine evacuation with misoprostol during radiotherapy for cervical cancer in pregnancy.

Radiotherapy as definitive treatment for invasive cervical cancer during pregnancy causes spontaneous abortion in most cases. Surgical evacuation of the uterus is indicated when abortion does not occur, exposing patients to additional morbidity. Two Latin American women, diagnosed with FIGO stage IB2 cervical cancer at approximately 15 weeks gestation, underwent radiotherapy with radiosensitizing chemotherapy. After intrauterine fetal demise was detected, both women underwent induction with misoprostol. Results included one complete abortion and one incomplete abortion without complications or delays in treatment. These cases demonstrate that induction with misoprostol appears to be a safe and effective alternative to surgical evacuation of the uterus when spontaneous abortion fails to occur during radiotherapy for locally advanced cervical cancer.

Abortifacient Agents, Nonsteroidal↗
PubMedDate not supplied

Selection of an appropriate initial test cutoff concentration for workplace drug urinalysis--Cannabis example.

Apparent analyte concentration (equivalent of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid [9-THC-COOH]) obtained by radioimmunoassay (RIA) for cannabinoids using reagents manufactured at four different periods (from the same manufacturer) and specific 9-THC-COOH concentration as determined by GC/MS are examined for the significance of their correlation. The resulting regression equations are then used to estimate the apparent RIA analyte concentrations of reagents manufactured at different time periods that are equivalent to a specific 9-THC-COOH concentration. Correlation coefficients of the regression analysis improve from approximately 0.4 to 0.7 in parallel with the increasing reagent specificity. The apparent RIA analyte concentrations that correspond to 15 ng/mL 9-THC-COOH decrease from about 110 to 50 ng/mL again in parallel with the increasing reagent specificity. These findings empirically demonstrate that reagent specificity is the determining factor of the resulting apparent RIA analyte concentration when testing samples that contain 9-THC-COOH and other metabolites (derived from marijuana exposure). Thus, if the 9-THC-COOH concentration as determined by GC/MS is of primary concern, the initial test cutoff concentration should be adjusted in accordance with the specificity of the reagent used.

Dronabinol↗
PubMedDate not supplied

High-risk endometrial cancer in young indigent women.

OBJECTIVE: The aim of this study was to evaluate a different prevalence and clinical pattern of high-risk endometrial cancer in an indigent population of young women. METHODS: Charts of 71 consecutive patients, treated for endometrial adenocarcinoma during a 6-year period, were reviewed. The patients were divided into two groups contingent upon age--(i) those who were below 40 years and (ii) those who were over 40. Based on histological type, grade, and stage, both groups were subdivided into a low, intermediate, or high-risk cancer category. RESULTS: Of the 13 (18.3%) patients in the younger age group, five patients (38.4%) had high-risk endometrial cancer, compared to only eight patients (13.8%) in the older age group. CONCLUSION: In contradiction to previous reports, our results show that a higher proportion of young indigent women diagnosed with endometrial cancer have a high-risk cancer. Delay in diagnosis can explain only some of the discrepancies in the special clinical pattern of endometrial cancer among this population. Other possible explanations include nutritional differences, genetic susceptibility, immunological status, and high-risk behavior. More epidemiological studies are needed for complete understanding of the unfavorable outcome of endometrial cancer in these young women.

Adenocarcinoma↗
PubMedDate not supplied

Clinicopathologic analysis of mullerian adenosarcoma: the M.D. Anderson Cancer Center experience.

The records of 41 patients diagnosed with adenosarcoma of the female genital tract between 1982 and 1996 were reviewed. The median age at diagnosis is 51 years (range, 14-84). The most common symptom is vaginal bleeding (71%). Clinical signs at presentation include pelvic mass (37%), uterine polyps (29%), and enlarged uterus (22%). In 71% of patients, the tumor originates from the uterus. Other sites include ovary (15%), pelvis (12%), cervix (2%). A history of thyroid cancer, benign ovarian cyst, and polycystic ovarian disease is found more frequently than expected in this patient population, whereas no relationship to endometriosis is observed. Surgery is the mainstay of treatment, but platin-based chemotherapy given upfront in inoperable patient has definite efficacy. An overall response rate of 92.5% was observed after primary therapy (surgery with or without radiotherapy, and/or chemotherapy), with a median survival of 48 months (range, 1-174). Thirty-eight percent of patients had recurrent disease. The median time to recurrence is 12 months (range, 5-132). Although 60% of patients with recurrence achieved a complete remission after treatment, only 1 (8%) is alive without disease, and 3 (22%), with disease at the time of this analysis. In our series, histologic sarcomatous overgrowth is a predictor of poor prognosis (p<0.03), however myometrial invasion and stage of disease seem to be of less prognostic significance. Adenosarcoma is a tumor with a fair prognosis. Most tumor can be cured with surgery, but recurrence carries a bad prognosis.

Adenosarcoma↗
PubMedDate not supplied

Competency-based learning for the surgical assistant.

In the first of two articles about the benefits and drawbacks of occupational standards, the authors describe a competency-based programme of continuing education for surgical assistants. The structure and content of the modules offered are discussed and the authors emphasise the validation of the courses by institutions of higher education. Next week's article will examine occupational standards in relation to professional development.

Competency-Based Education↗