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Biomedical subjects

L Peterson

Publications and source records attributed to L Peterson.

At least 145 records · Page 8Linked to original sources
PubMed1987

Effects of unilateral arterial infusion of GH and IGF-I on tibial longitudinal bone growth in hypophysectomized rats.

We have studied the effect of local arterial infusion of bacterially produced human growth hormone (hGH), insulinlike growth factor I (IGF-I), or pituitary-derived ovine prolactin (oPRL) on longitudinal bone growth of hypophysectomized rats. The substances were infused during a 14-day period by osmotic mini-pumps through a catheter which was implanted into the femoral artery of one hindlimb. Longitudinal bone growth was measured by the intravital marker tetracycline. Infusion of 1 microgram hGH per day stimulated bone growth only of the treated limb and not of the uninfused contralateral limb. Infusion of 10 micrograms hGH per day also stimulated unilateral longitudinal bone growth, but the uninfused contralateral limb also showed a significant growth response, probably because local administration of GH at this dose caused a significant elevation of GH in the systemic circulation. As a result, the differential growth response between the GH-treated and untreated limbs decreased compared to rats that were infused with 1 microgram hGH per day. Unilateral arterial infusion of 5 micrograms human IGF-I or 10 micrograms oPRL per day did not produce a significant growth response. The results of the present study confirm the observation by Schlechter and co-workers, who demonstrated that unilateral arterial infusion of GH maintained tibial cartilage width following hypophysectomy in the rat. The results of Schlechter and coworkers and the results of the present study show that GH in vivo stimulates epiphyseal cartilage growth directly. However, an increased local production of insulinlike growth factors is probably of importance for the expression of the direct effect of GH on longitudinal bone growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Not safe at home: behavioral treatment of a child's fear of being at home alone.

The behavioral treatment of a child's fear of being alone in her own home is described. Gaining control over frightening images and increasing coping behaviors such as relaxation, distraction, and self-instruction during progressive behavioral rehearsal reduced self-reported fears and increased adaptive responding. The utility of such techniques, particularly control over frightening imagery, is discussed.

Accident Prevention↗
PubMed1987

Transient atypical lymphocytosis in patients with emergency medical conditions.

Lymphocytosis in older adults is unusual and frequently indicates chronic lymphocytic leukemia or other lymphoproliferative disorder. This report describes 73 patients, aged 43 to 93 years, who presented with emergency medical conditions and who had absolute lymphocytosis, with absolute lymphocyte counts ranging from 4.1 to 12.9 X 10(9)/L (4100 to 12,900/mm3). The lymphocytosis was characterized morphologically by atypical lymphocytes and was transient, followed, in most instances, by a neutrophilia. Most of the patients presented with serious cardiac conditions; the remaining presented with other critical disorders including status epilepticus and traumatic injuries. The mortality rate was high (50%). The lymphocytosis in some patients was probably secondary to the administration of epinephrine. The lymphocytosis in those not receiving epinephrine may have represented a physiologic reaction to severe stress.

Adult↗
PubMed1986

Identification of distinct receptors for two hemopoietic growth factors (granulocyte colony-stimulating factor and multipotential colony-stimulating factor) by chemical cross-linking.

Granulocyte colony-stimulating factor (G-CSF) and multipotential colony-stimulating factor (multi-CSF or interleukin 3) are two members of a family of hemopoietic growth and differentiation factors. Using biologically active radioiodinated derivatives and chemical cross-linking (predominantly with the homobifunctional reagent disuccinimidyl suberate) followed by gel electrophoresis and autoradiography, receptors for these two factors have been identified. The G-CSF receptor was identified as a single subunit protein of Mr approximately 150,000 while two molecular species able to specifically cross-link to 125I-multi-CSF were identified of Mr approximately 75,000 and 60,000. For both CSFs specificity of formation of cross-linked species was demonstrated by showing that the homologous unlabeled CSF (but not other CSFs) competed for formation of the complexes with the appropriate dose-response relation, by showing that saturation occurred over the appropriate range of 125I-CSF concentration and by showing that the cellular specificity of CSF binding paralleled that for cross-linked complex formation. The formation of cross-linked complexes was dependent on the concentration and type of chemical cross-linker, especially for cross-linking of 125I-multi-CSF. Based on a number of criteria it is suggested that the two species cross-linked to 125I-multi-CSF do not represent receptors of different affinity but, rather, two noncovalently associated subunits of a receptor complex.

Animals↗
PubMed1986

Children's concepts of physical illness: a review and critique of the cognitive-developmental literature.

Cognitive-developmental studies relevant to children's concepts of physical illness are reviewed and critiqued. Although numerous methodological weaknesses make firm conclusions difficult, most data appear to suggest that children's concepts of illness do evolve in a systematic and predictable sequence consistent with Piaget's theory of cognitive development. Methodological weaknesses identified include poor description of samples, assessment instruments, and procedures; lack of control over potential observer bias, expectancy effects, and other confounding variables; and minimal attention to reliability and validity issues. Increased methodological rigor and a further explication of the specific and unique ways in which children's concepts of illness develop over the course of cognitive development could substantially increase the value of these studies for professionals in pediatric health care settings.

Adolescent↗
PubMed1986

An information seeking disposition in child surgery patients.

Several studies in the last decade have demonstrated the importance of considering an information seeking versus information avoiding coping dimension in adult medical patients. However, there have been few empirical demonstrations of such a dimension in children. The present study utilized the Coping Strategies Interview to assign an information seeking score to child elective surgery patients. This information seeking score was related to several parent-rated variables, including the child's historical success in coping with medical procedures, the child's typical preference for information acquisition, and the child's typically emitted coping behaviors. In addition, the information seeking score was related to question asking and discussion of medical procedures as rated by an objective observer during the blood test, by the nurse during anesthesia induction, and by the parent during recovery from surgery. It was strongly related to the information acquired prior to hospitalization. Information seeking was also related to stress responses, such that high information seeking scores predicted more adaptive behaviors prior to the blood test. This cross-rater and cross-situation validation suggests the existence of an information seeking dimension in children and the utility of considering this dimension in future research.

Adaptation, Psychological↗
PubMed1986

Newborn screening for hemoglobin abnormalities. A comparison of methods.

Peripheral blood from 1,000 newborn infants of black (641) and Southeast Asian (359) ancestry were screened for hemoglobin variants. Results obtained from the combination of cellulose acetate (CAC) and citrate agar (CAG) electrophoresis were compared with isoelectric focusing (IEF) electrophoresis. There was complete agreement between the two methods on assignment of Hb S trait, Hb C trait, Hb E trait, and homozygous Hb E. IEF identified small amounts of Hb A in two newborn infants with Hb S-beta + thalassemia; the CAC and CAG electrophoretic patterns were indistinguishable from sickle cell anemia. One hundred twenty newborn infants with Hb Bart's were detected by IEF; 51 of these were found on CAC. Although IEF was more sensitive in detecting small amounts of hemoglobin, it is not clear if the improvement in detection warrants adopting this form of electrophoresis for routine screening of newborn infants.

Electrophoresis↗
PubMed1986

Antigen-induced experimental septic arthritis in rabbits after intraarticular injection of Staphylococcus aureus.

With the Dumonde-Glynn model of antigen-induced arthritis, a rabbit model was developed to examine the histopathologic differences between normal and arthritic joints in the same animal infected by intraarticular injections of Staphylococcus aureus. Microscopic examination of whole joint sections and a quantitative histopathologic scale were used to compare changes in all the articular components of 17 normal and 17 arthritic joints infected for less than two weeks. The histological changes were more severe in infected arthritic joints than in infected normal joints (mean +/- SD total histology score, 13.8 +/- 2.4 and 9.3 +/- 4.0, respectively; P less than .001). In infected arthritic joints, subsynovial abscesses extended into subchondral bone via the pannus of chronic synovitis at articular margins and intraarticular attachments of cruciate ligaments, rather than by initial cartilage destruction and direct extension into subchondral bone.

Abscess↗
PubMed1986

Use of technetium-99m methylene diphosphonate and gallium-67 citrate scans after intraarticular injection of Staphylococcus aureus into knee joints of rabbits with chronic antigen-induced arthritis.

Numerous clinical studies have questioned the ability of radionuclide scans to differentiate septic from aseptic joint inflammation. A clinical study may not be able to document an underlying disease process or duration of infection and, thus, may make conclusions about the accuracy of scan interpretations open to debate. In this study, the Dumonde-Glynn model of antigen-induced arthritis in rabbits was used as the experimental model to study technetium and gallium scans in Staphylococcus aureus infection of arthritic and normal joints. Gallium scans were negative in normal rabbits, usually negative in antigen-induced arthritis, but positive in septic arthritis. The bone scan was usually negative in early infection but positive in late septic arthritis, a finding reflecting greater penetration of bacteria into subchondral bone because of the underlying inflammatory process.

Animals↗
PubMed1986

Phase I clinical trial of CO17-1A monoclonal antibody.

Twenty patients with metastatic gastrointestinal cancer received one or more weekly infusions of 400 mg CO17-1A monoclonal antibody. The most common side effect was mild gastrointestinal symptoms in 9/20 patients. Two of five patients receiving three weekly infusions had reversible anaphylactic reactions at the time of their third infusion. The pharmacokinetics of the antibody were similar at the first, second or third infusion. Human antibody to 17-1A occurred in 17/20 patients with 11/20 having antibody detectable by 8 days following initial infusion. Thus, one or two infusions (weekly) of large doses of 17-1A were well tolerated but allergic responses limit ability to administer therapy by 15 days post-initial infusion.

Animals↗
PubMed1986

Trauma in sport.

Explore the source record for details and available documents.

Athletic Injuries↗
PubMed1985

Microparticulate-induced phlebitis. Its prevention by in-line filtration.

We carried out a double-blind prospective study of the effect of a filter on the incidence of phlebitis associated with intravenous infusion in 541 patients. A total of 277 patients received infusions through intravenous sets with 0.22-micron IVEX-HP filters, and 264 received infusions without filters. Each infusion was evaluated daily for a maximum of three days. The incidence of phlebitis on Days 1, 2, and 3 of the study was 14.3, 31.1, and 27 per cent for patients receiving infusions without filters and 6.8, 9.7, and 11.3 per cent for those receiving infusions through the filters (P less than 0.001). Thus, the incidence was reduced by approximately two thirds in the patients who received infusions through the IVEX-HP filters. We conclude that infusion-related phlebitis is a pervasive problem in hospitalized patients, and that it is usually caused by microparticulate components that are present in the infusion fluids and can be removed by in-line filtration.

Adolescent↗
PubMed1985

Childhood depression: peer reactions to depression and life stress.

The present study investigated children's responses to a peer's childhood depression. Younger children in third and fourth grade and older children in fifth and sixth grade were exposed to one of four films. The four films portrayed a female peer who was either depressed or not depressed and who had experienced numerous recent life stresses or no recent life stress. Overall, children rated the depressed peers as less likeable and attractive, as engaging in fewer positive current and future behaviors, and as needing therapy more than a nondepressed peer. There was a tendency to rate the depressed peer with high life stress more positively than the depressed peer with low life stress; this tendency decreased with age. Girls rated all of the peers and especially the stressed peers more positively than did the boys. The results are discussed in terms of the implications of children's social interaction for the initiation or maintenance of childhood depression.

Adaptation, Psychological↗
PubMed1985

Applicability of laser to assist coronary balloon angioplasty.

Severe atherosclerotic obstructed coronary artery disease (CAD) may preclude passage of a balloon catheter for transluminal coronary angioplasty (TCA). Since lasers have been shown to effectively vaporize CAD plaque, the initial application of laser to effect a lumen large enough to accommodate the angioplasty catheter for further dilatation was explored. Eleven postmortem human CAD segments which did not permit passage of a 1.33 mm shaft diameter angioplasty catheter were studied. Argon laser radiation (14 to 90 J) transmitted via 400 micron core diameter quartz fiber onto the stenotic channel of 0.58 mm created a vaporized lumen of 1.77 mm (mean increase of 1.31 +/- 0.25 mm, p less than 0.001). The laser procedure allowed the balloon angioplasty catheter to be pushed into the stenosis. TCA was then performed (7 atm, 45 seconds) and expanded the channel to 2.12 mm (additional mean increase of 0.38 +/- 0.07 mm, p less than 0.001). In terms of percent luminal narrowing, laser radiation reduced obstruction from 80% to 45% (mean difference of -38.7 +/- 4.6%, p less than 0.001), and TCA caused a further decrease to 37% (mean difference of -9.3 +/- 1.9%, p less than 0.001). Thus, in tight atherosclerotic lesions, the laser may be useful in creating an initial opening enabling the placement of the balloon angioplasty catheter which, in turn, can further dilate the lased stenotic coronary lumen.

Angioplasty, Balloon↗
PubMed1985

Nonendemic adult T-cell leukemia/lymphoma in the United States: report of two cases and review of the literature.

Adult T-cell leukemia/lymphoma (ATLL) is a recently described distinct clinicopathologic entity characterized by a leukemic or lymphomatous proliferation of hyperlobulated peripheral T-cells, which is usually widespread at presentation and is associated with infection by a type C retrovirus. ATLL rarely is described outside of endemic regions, which include southwestern Japan, the Caribbean region, and the southeastern United States. The authors report the clinical, pathologic, and immunologic features of two cases of nonendemic ATLL that occurred in patients from the midwest United States. One patient was a 16-year-old white girl from rural Iowa, and the other was a 46-year-old white man from rural Minnesota. The features of 13 other probable nonendemic ATLL cases from the United States were compiled and reviewed. In the United States, nonendemic ATLL occurred in widespread geographic locations, affected mostly white people, and was characterized by an aggressive course with generalized adenopathy, blood and bone marrow involvement, and hepatosplenomegaly at presentation. Skin involvement was present in one-fourth of the patients. Hypercalcemia was rare. Although antibodies to type C retrovirus were detected in three of the five patients tested, the available data is not sufficient to establish a conclusive association between nonendemic ATLL and type C retrovirus infection.

Adolescent↗