Biomedical subjects

T Olson

Publications and source records attributed to T Olson.

At least 19 recordsLinked to original sources

PubMed2000

Glyphosate-tolerant corn: the composition and feeding value of grain from glyphosate-tolerant corn is equivalent to that of conventional corn (Zea mays L.).

Glyphosate-tolerant (Roundup Ready) corn line GA21 has been developed by genetic modification to tolerate glyphosate, the active ingredient in Roundup herbicide. The purpose of this study was to evaluate the compositional and nutritional safety of corn line GA21 compared to that of conventional corn. Compositional analyses were conducted to measure proximate, fiber, amino acid, fatty acid, and mineral contents of grain and proximate, fiber, and mineral contents of forage collected from 16 field sites over two growing seasons. The nutritional safety of corn line GA21 was evaluated in a poultry feeding study conducted with 2-day old, rapidly growing broiler chickens, at a dietary concentration of 50-60% w/w. Compositional analysis results showed that, except for a few minor differences that are unlikely to be of biological significance, the grain and forage of GA21 corn were comparable in their composition to that of the control corn line and to conventional corn. Results from the poultry feeding study showed that there were no differences in growth, feed efficiency, adjusted feed efficiency, and fat pad weights between chickens fed with GA21 grain or with parental control grain. These data taken together demonstrate that Roundup Ready corn is as safe and nutritious as conventional corn for food and feed use.

Amino Acids↗

PubMed1998

Chart audit of inpatient treatment of schizophrenic patients: implications for development of coordinated care paths.

This study offers important information regarding the standard of care provided to schizophrenic patients treated at one inpatient facility. The findings were particularly useful in the development of a care path for this specific population. Areas for improvement identified in this research include medical tests, master treatment planning, documentation of care, patient teaching, and discharge planning. Given the limited health care dollars and the lack of a cure for schizophrenia, this research emphasizes the fact that treatment guidelines need to be aggressively tested as to their relevance to practice.

Adult↗

PubMed1997

Development of a scientifically valid coordinated care path.

OBJECTIVE: The goal of this study was to develop a method to scientifically create and validate a coordinated care path for use within any hospital setting. BACKGROUND: In an attempt to reduce the costs associated with high-volume and high-risk diagnosis, attention was focused on reducing patients' length of stay in the hospital. A method to reduce length of stay uses a coordinated care path. A path is a guideline used to manage the clinical care of selected patients. The literature is relatively silent regarding studies that have scientifically validated the use of these paths. METHODS: This project used a content validity method to validate the care path. Using current research findings, best practice standards both locally and nationally, a transdisciplinary team developed practice guidelines that included sequencing, timing of interventions, and expected patient outcomes. The path was rated by local and national experts using a four-point rating scale. Using Lynn's proportion of experts table computations, the validity of the path and each of its components was determined. RESULTS: Of 161 items on the care path, 10 were not validated. The experts validated the instrument as a whole. Of the 161 items, 151 were validated. This is an instrument validation rate of 0.94. No additional changes or modifications to the path were suggested by the experts. The transdisciplinary team addressed the nonvalidated items. This method can be used to develop other coordinated paths for other diagnostic groups.

Critical Pathways↗

PubMed1996

Stem cell factor (SCF) synergizes with megakaryocyte colony stimulating activity in post-irradiated aplastic plasma in stimulating human megakaryocytopoiesis.

Plasma obtained from lethally irradiated animals contains a megakaryocyte (MK) growth factor which has recently been identified as the ligand for the c-mpl receptor and has been named thrombopoietin (TPO). We demonstrate that post-irradiation aplastic canine plasma (PICS-J) and plasma from a human subject (ML) who was accidentally exposed to lethal irradiation, contain high levels of this activity, which support both MK proliferation and maturation in a dose-dependent manner. These plasma were far more active in stimulating human MK colony formation than other types of thrombocytopenic plasma or a number of exogenously added human recombinant cytokines and their combinations. The addition of stem cell factor (SCF), which alone has a minimal stimulatory affect, to post lethal-irradiation plasma provided a synergistic stimulation of megakaryocytopoiesis both in colony assays and liquid cultures. In colony assays, the combination of SCF with PICS-J or ML almost doubled the number of burst forming units (BFU-MK) and provided a 1.5-fold increase in colony forming units (CFU-MK). A 1.6-fold increase in the number of CD34+ BM cell-derived MK colonies was also elicited. In liquid cultures, the presence of both SCF and PICS-J or ML induced the appearance of a high proportion of CD34+ (6.56% vs 0.6% control) and CD41+ (3.5% vs 1.2% control) cells after 3 days in culture. By day 10, 66.8 x 10(4) CD41+ cells and 29.8 x 10(4) CD34+ cells were derived from 2 x 10(6) BMMC originally seeded. We propose that these unique plasma, which do not contain elevated level of IL-6, IL-3, GM-CSF, IL-1 beta, erythropoietin or SCF, probably contain high levels of TPO. The addition of SCF to the post-irradiation plasma provides a synergistic stimulation of megakaryocytopoiesis which may become relevant for future clinical application.

Anemia, Aplastic↗

PubMed1996

Fundamental and special: the dilemma of psychiatric-mental health nursing.

This article explores the tension between defining psychiatric-mental health nursing as fundamental to the discipline yet also special, an historic dilemma that continues to influence efforts to establish a secure place for the specialty. Analysis focuses on the formative work of three pioneers in this field, using primary and secondary documents in the archives of the Center for The Study of The History of Nursing. The findings of this research indicate that early reliance on interpersonal theory provided an uncertain basis for differentiating psychiatric-mental health nursing from other areas of nursing practice.

History, 20th Century↗

PubMed1996

Genome duplication in soybean (Glycine subgenus soja).

Restriction fragment length polymorphism mapping data from nine populations (Glycine max x G. soja and G. max x G. max) of the Glycine subgenus soja genome led to the identification of many duplicated segments of the genome. Linkage groups contained up to 33 markers that were duplicated on other linkage groups. The size of homoeologous regions ranged from 1.5 to 106.4 cM, with an average size of 45.3 cM. We observed segments in the soybean genome that were present in as many as six copies with an average of 2.55 duplications per segment. The presence of nested duplications suggests that at least one of the original genomes may have undergone an additional round of tetraploidization. Tetraploidization, along with large internal duplications, accounts for the highly duplicated nature of the genome of the subgenus. Quantitative trait loci for seed protein and oil showed correspondence across homoeologous regions, suggesting that the genes or gene families contributing to seed composition have retained similar functions throughout the evolution of the chromosomes.

Chromosome Mapping↗

PubMed1995

A novel method to purify recombinant vascular endothelial growth factor (VEGF121) expressed in yeast.

VEGF is a potent mitogen for vascular endothelial cells in vitro and acts as an angiogenic factor in vivo. VEGF121 differs from the other isoforms in that it lacks the heparin-binding domain. To study the potential differences in biological functions of the VEGF isoforms, we cloned and expressed VEGF121 in a yeast expression system. VEGF121 was secreted from the yeast cells as a homodimer with a molecular weight of 34-36 kDa. By taking advantage of the consecutive histidine residues present at position 11 and 12 in VEGF, a novel method of purification using Nickel affinity chromatography was developed. Since all the isoforms of VEGF have an identical amino terminal end, this method can be used to purify not only VEGF121 but also the other forms of VEGF. The level of expression achieved using this system was as high as 40 mg/L. The recombinant protein was biologically active in stimulating the in vitro proliferation of vascular endothelial cells and positively reacted to an antiserum made against recombinant VEGF165.

Cell Division↗

PubMed1995

Transferrin-antibody fusion proteins are effective in brain targeting.

In the present study, the receptor binding potential of transferrin (Tf) was linked to an antibody binding specificity. Human Tf was fused to mouse-human chimeric IgG3 at three positions: at the end of heavy chain constant region 1 (CH1), after the hinge, and after CH3. The resulting Tf-antibody fusion proteins were able to bind antigen and the Tf receptor. The CH3-Tf fusion protein showed no complement-mediated cytolysis but possessed IgG receptor I (Fc gamma RI) binding activity. Most importantly, all of the fusion proteins demonstrated significant uptake into brain parenchyma, with 0.3% of the injected dose of the hinge-Tf fusion protein rapidly targeted to the brain. Recovery of iodinated CH3-Tf fusion protein from the brain parenchyma demonstrated that the fusion proteins can cross the blood-brain barrier intact. The binding specificity of these fusion proteins can be used for brain delivery of noncovalently bound ligands, such as drugs and peptides, or for targeting antigens present within the brain.

Animals↗

PubMed1995

High-dose-rate brachytherapy in childhood sarcomas: a local control strategy preserving bone growth and function.

The administration of external beam radiation therapy (EBRT) has been an integral part of the successful treatment of childhood sarcomas. However, EBRT has severe late morbidity in the developing child. In an attempt to deliver adequate tumoricidal radiation while preserving bone growth and organ function, 13 children with diverse sarcomas were treated with high dose rate brachytherapy (HDR). Seven patients had rhabdomyosarcoma and six patients had other soft tissue sarcoma variants. All patients were treated with disease-appropriate chemotherapy, usually according to the intergroup Rhabdomyosarcoma Study. Eleven patients received fractionated 36 Gy HDR alone at a mean of 3.5 months from diagnosis. Two patients received 10-12.5 Gy intraoperative HDR brachytherapy and additional 27 Gy EBRT. Nine of 11 patients in first remission have had no recurrences. One died of recurrent pulmonary metastases. The other patient that did recur is disease-free 21 months post-recurrence. Two additional patients were treated with HDR after tumor recurrence. One patient with recurrent Ewing's sarcoma, relapsed and died. The second is disease free 3 months after autologous bone marrow transplant. Grade 1 morbidity occurred in 46%, Grade 2 in 15%, and Grade 3 in 8% of the children, while relatively good bone and organ growth was maintained. The combination of conservative surgery, chemotherapy, and HDR offers the potential for disease control in young children while preserving bone growth and organ function.

Brachytherapy↗

PubMed1995

Expression of biologically active human vascular endothelial growth factor in yeast.

Vascular endothelial growth factor (VEGF) is a glycoprotein consisting of two identical polypeptide chains linked by a disulfide bond. The unique biological activities of VEGF include its potent mitogenic and permeability inducing properties specific for the vascular endothelium. VEGF is implicated in tumor angiogenesis, wound healing, and the stimulation of collateral vessel formation at the site of arterial occlusion. Therefore, in order to produce large quantities of biologically active VEGF, a splice variant (VEGF165) was cloned and expressed in a yeast expression system. The coding region of VEGF165 was isolated from U937 cells by RT-PCR, sequenced and then cloned into the yeast expression vector pHILS1. VEGF165 was secreted into the medium as a dimer. Recombinant VEGF reacted to antibodies raised against the N-terminal and C-terminal synthetic polypeptides of human VEGF. As much as 35-40 mg/L of purified VEGF could be obtained from the yeast expression system. The recombinant protein was biologically active in inducing vascular endothelial cell proliferation in vitro and permeability changes in vivo.

Amino Acid Sequence↗

PubMed1990

Competing paradigms and the St Luke's Alumnae Association minutes, 1895-1916.

This study was designed to explore the relationship between the minutes of the alumnae association of a training school for nurses, from 1895 to 1916, and the occupational evolution of nursing. The members of the St Luke's Alumnae Association, even in their initial statement of purpose, consistently affirmed their ties to other nurses, thus implicitly supporting the cause of trained nursing. But the cause of trained nursing was not the same as that of professional nursing. These findings support the usefulness of the "work group" paradigm vs the paradigm of professionalization in attempting to describe accurately the occupational evolution of nursing as portrayed in the minutes.

Documentation↗

PubMed1990

A sojourn with two nurses of the Virgin Islands.

The experiences shared by Ms. Mitchell and Ms. Milligan represent a combined total of more than 80 years of work in nursing. As an introduction to nursing history in a small but vital part of the world, their observations suggest exciting ideas for further research. Such research might include an in-depth exploration of the history of the islands' system of nursing education, a study of the influence of the various island cultures on nursing education and practice, or a comparison between nursing practice in the islands and the mainland. It is hoped that this article might encourage others to explore further the rich history of nursing in the U.S. Virgin Islands.

History of Nursing↗

PubMed1990

Quantitative and functional assays compared for determination of zymogen and activated human protein C.

We evaluated quantitative and functional assays for protein C, using either purified protein C samples or pooled normal plasma as assay standards. The purified protein C samples were examined as the zymogen form and after activation by thrombin. Mass concentrations of protein C were determined by amino acid analysis and confirmed by enzyme-linked immunosorbent assay (ELISA). Functional activity was assessed in both standard clot inhibition and amidolytic assays. The accuracy and precision of the ELISA was acceptable, with all three preparations of protein C having similar linear curves. The clot inhibition assay demonstrated marked variability when used according to the manufacturer's instructions; however, modifications to the protocol significantly decreased the CV, to less than 10%. Both activated protein C and the zymogen gave linear standard curves. Pooled normal human plasma gave a nonlinear curve, which contributed to inaccurate sample recoveries. We obtained the most nearly accurate recoveries when we used activated protein C as the assay standard. Amidolytic assays provided no insights into the appropriateness of the preparations for that assay format. A uniform, consistent source of protein C, e.g., recombinant activated protein C, would be useful for standardizing all assays of protein C.

Enzyme Precursors↗

PubMed1986

Cryptosporidial infections in captive wild animals.

Neonatal diarrhea was an important cause of morbidity and mortality in a hand-rearing facility for exotic ruminants at the San Diego Wild Animal Park. Studies undertaken to determine the causes of the problem revealed that oocysts of Cryptosporidium sp. were demonstrable in auramine O stained fecal smears from 52 of 183 (28.4%) animals examined. Cryptosporidial infection was identified in 21 of 40 species of exotic ruminants with diarrhea. In addition, cryptosporidia were associated with gastroenteric disease in two primates and two reptiles. It was observed also that auramine O stained coccidial oocysts of the genus Eimeria, which were present in five of 183 (2.7%) of the specimens examined.

Animals↗

PubMed1985