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Biomedical subjects

L Armstrong

Publications and source records attributed to L Armstrong.

88 records · Page 5Linked to original sources
PubMed1983

Osteogenesis after bone and bone marrow transplantation. The ability of ceramic materials to sustain osteogenesis from transplanted bone marrow cells: preliminary studies.

The ability of four different ceramic materials to support osteogenesis when placed with bone marrow into an intermuscular site was studied. In the search for biodegradable porous ceramic materials that could be used for bone replacement and that would slowly be replaced by bone by means of "creeping substitution," the authors fabricated porous alumina, calcium aluminate, calcium hydroxyapatite, and tricalcium phosphate. Specially shaped compacts, impregnated with autologous bone marrow, were inserted into intermuscular pouches in rabbits and retrieved after 14-182 days. Newly formed bone was found within the contents of the well after 14 days and was visible at all times up to 182 days. The bone was frequently found to have adhered to the ceramic and to have penetrated the interior if the pore size was greater than 100 micron. Further investigation of the use of synthetic materials in bone replacement is warranted due to the finding that some porous ceramic material permit bony ingrowth from autologous marrow cells.

Aluminum↗
PubMed1981

Lipogranuloma of the male genitalia.

A case of lipogranuloma of the external genitalia is presented. The history and histological features suggest that the exogenous lipid was introduced by the topical application of a baby oil used after minor trauma to the penis. Initial treatment by steroids and immunosuppressive agents was followed by complete excision of the granuloma.

Adrenal Cortex Hormones↗
PubMed1980

Significance of plasma fibrinopeptide A (fpA) in patients with malignancy.

In 124 patients with various types of malignancy, fpA and delta fpA were measured. In 35 of these patients the effect of heparin injection on fpA and delta fpA was studied. All patients were ambulant without clinical signs of venous thromboembolism or DIC and had not received cytostatic, anticoagulant, or radiotherapy recently. In about 75% of these patients, fpA was elevated, whereas in the blood of one third of the patients, both elevated fpA levels and accelerated delta fpA were detected. Eight of the 45 patients with accelerated delta fpA (and elevated fpA) presented laboratory signs of low-grade DIC. In the patients taken at random for heparin administration, delta fpA normalized upon heparin injection, whereas in the majority of patients, irrespective of the fpA-generation rate, fpA levels were not affected by "adequate" heparinization. These results indicate that (1) about 30% of the (selected) patients admitted to our cancer clinic present with evidence of intravascular thrombin activity and (2) in 70% of these patients fpA is generated, at least in part, at a site not accessible to heparin. In addition 95% of patients with active metastatic disease showed an elevated fpA, whereas 90% of cancer patients in remission and 80% of patients without metastasis had a normal fpA, indicating that fpA can potentially be used to estimate the spread and the activity of the malignant process.

Adolescent↗
PubMed1970

Control of heparin therapy.

Heparin therapy in 114 patients was controlled by daily blood tests-the whole blood coagulation time, kaolin-activated partial thromboplastin time of plasma, and plasma heparin assay. Bleeding episodes occurred in 7 out of 92 patients (7.6%) who had normal haemostatic mechanisms before therapy and in 11 out of 22 patients (50%) with defective haemostasis, mostly due to intravascular coagulation or renal failure. The dose of heparin ranged from 20,000 to 60,000 units in each 24-hour period. In some patients bleeding was related to overdosage, but in others the laboratory tests indicated satisfactory or suboptimal dosage at the time of bleeding. Though there were positive correlations between the results of the three tests, these were not close, and no one test was preferable. Hence laboratory control of heparin therapy is unsatisfactory and patients may bleed despite careful control of the dose by all three methods.

Acute Kidney Injury↗
PubMedDate not supplied

Parkinson's disease and aided AAC: some evidence from practice.

Clinical observation that people with Parkinson's disease (PD) seem to have different training needs from other adult client-groups in developing effective use of aided augmentative and alternative communication (AAC) was the catalyst for this study. There is little good-quality research evidence available on the effectiveness (or lack of effectiveness) of aided AAC use by those with PD. One of the main aims of this preliminary study, therefore, was to elicit the experiences and attitudes of speech and language therapists in this specific area of their practice as the basis for future efficacy research and clinical practice. Thirty speech and language therapists were questioned about their experience of introducing low- and high-tech AAC devices to this client-group. Of particular interest was the discovery of the factors identified by the therapists as influencing their introduction of aided AAC to someone with PD and affecting implementation and successful use. The factors reported were both disease-specific (e.g. motor problems) and more general factors (e.g. carer support) relevant to the process of introducing aided AAC to other adult client-groups. Implications for future research and practice are discussed. Some research questions are posed and the inclusion of people with PD and their carers in practice development is promoted.

Attitude of Health Personnel↗
PubMedDate not supplied

The effect of captopril on the oxidation of plasma lipoproteins.

The antihypertensive drug captopril was found to inhibit the oxidation of low density lipoproteins by copper in a dose dependent manner in vitro. Up to 65% inhibition of oxidation was observed at the concentration of 100 micrograms/ml of captopril. During subsequent studies with patients, captopril protected low density lipoproteins against oxidation slightly better than enalapril, although this difference was not statistically significant. Captopril had no effect on the levels of Lp(a) as compared to the levels established during enalapril treatment.

Aged↗
PubMedDate not supplied

Establishing therapeutic boundaries as patient advocates.

Pediatric nurses often struggle to define their advocacy role with patients and their families. Nursing is based on the therapeutic use of self and caring. An unclear therapeutic relationship can undermine nurses' advocacy efforts. Nurses are encouraged but often not guided about staying within the parameters that define a professional and therapeutic relationship between the nurses and the patient/family. Examining the impact of unclear boundaries on the patient/family relationship and the nurse's ability to serve as an advocate provides the basis for suggested constructive strategies for addressing the related issues.

Child↗
PubMedDate not supplied

Efficacy of p53 adenovirus-mediated gene therapy against human breast cancer xenografts.

In response to DNA damage, p53 protein accumulates in the cell nucleus causing cells to undergo DNA repair or apoptosis, programmed cell death. Reintroduction of wild-type p53 into tumors with null or mutant p53 offers a novel strategy for controlling tumor growth, by inducing apoptotic death in neoplastic cells. The efficacy of a replication-deficient p53 adenovirus construct was tested against three human breast cancer cell lines expressing mutant p53, MDA-MB-231, -468, and -435. 231 and 468 cells were both highly transduced at a multiplicity of infection of 10. By contrast, 435 cells were rarely transduced. p53 adenovirus-mediated gene therapy was highly effective against 231 and 468 tumor xenografts in nude mice. At a total dose of 2.2 x 10(9) cellular infectious units (CIU), inhibition of 231 tumor growth was 86% (P < or = .01). Thirty-seven percent of that growth inhibition was due to p53, while 49% was adenovirus-specific. Inhibition of 468 tumor growth was 74% (P < or = .001). Forty-five percent of that inhibition was p53-specific, while 28% was adenovirus-specific. The ED50 values for 231 tumors and 468 tumor growth inhibition were 3 x 10(8) CIU and 2 x 10(8) CIU, respectively. Injection of p53 Ad into 231 or 468 tumors induced apoptosis. By contrast, growth inhibition in 435 tumors treated with p53 adenovirus was not significant, probably due to low adenovirus transduction. 231 and 435 cells both expressed high levels of alpha v, beta 1, beta 3, and beta 5 integrin subunits, ruling out lack of the appropriate integrins as the reason for the low infection rate in 435 cells. Our results demonstrate the ability of wild-type p53 to curtail cancerous cell growth in vivo in tumors expressing mutant p53. The ability of beta-gal Ad to infect tumor cells in vitro was generally predictive of in vivo p53 Ad efficacy.

Adenoviridae↗