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Biomedical subjects

P A Dunn

Publications and source records attributed to P A Dunn.

At least 19 recordsLinked to original sources
PubMed2003

Summary of the 2001-02 Pennsylvania H7N2 low pathogenicity avian influenza outbreak in meat type chickens.

H7N2 low-pathogenicity (LP) avian influenza (AI) virus was isolated from chickens submitted to the Pennsylvania Animal Diagnostic Laboratory System on December 4 and 5, 2001. The cases were from two broiler breeder flocks in central Pennsylvania that had clinical signs of an acute, rapidly spreading respiratory disease. Seroconversion to AI virus was detected on follow-up sampling. Subsequently, H7N2 LPAI virus was isolated in five different broiler flock cases submitted between December 14, 2001, and January 3, 2002. Clinical signs and lesions in broilers, when present, were compatible with multicausal respiratory disease. With the exception of one broiler flock that was processed, birds from all of the virus positive flocks were euthanatized in-house within 11 days of the original case submission date. Increased surveillance of poultry flocks within 10-mile radius zones centered at the foci of the positive farms continued until March 1, 2002. No additional cases were detected.

Animals↗
PubMed2000

Feldenkrais sensory imagery and forward reach.

To investigate the effect of sensory imagery on subsequent movement, a unilateral Fleldenkrais lesson of imaging a soft bristle brush passing over one half of the body and in which no movement occurred, was given to 12 naive subjects. Forward flexion for each side of the body was measured at a sit-and-reach box. For 8 and 10 subjects who reported the perception of a side as being longer and lighter following the sensory imagery, there was also a significant increase in the forward flexion range on that side.

Adolescent↗
PubMed1996

Surgical clips in planning the electron boost in breast cancer: a qualitative and quantitative evaluation.

PURPOSE: To evaluate, qualitatively and quantitatively, the role of surgical clips in planning the tumor bed electron boost in patients undergoing breast conserving surgery and radiotherapy. METHODS AND MATERIALS: In 50 patients, the excision cavity boundaries were marked by clips at surgery. The electron boost field was first planned using clinical information, aiming to achieve a margin of 2 cm, and its accuracy evaluated by screening the surgical clips and, if necessary, adjusting the field to encompass all clips with 2 cm margins. Orthogonal radiographs were take with solder wire delineating the clinical and screened fields and the scar. Hypothetical clinical and radiological fields, with 1 and 3 cm margins, were reconstructed on the radiographs. RESULTS: The clinical field was inadequate in 34 patients (68%). The precision of each clinical setup was quantified by two indices. The Normal Tissue Index defined the percentage of the clinical field comprised of tissue, beyond the tumor bed, not at high risk of local recurrence, and gave an estimate of potential spring of normal tissue: median 14.6% (range 0-83.0), 17 out of 50 > 25%; median 13% (range 0-70.7), 12 out of 50 > 25%; median 9.7% (range 0-59.8), 10 out of 50 > 25%, for 1, 2, and 3 cm margins, respectively. The Geographical Miss Index defined the percentage of the radiologically defined field, at high risk of local recurrence, not predicted by the clinical field, and gave an estimate of the extent of geographical miss: median 32.9% (range 0-83.5), 28 out of 50 > 25%; median 26.1% (range 0-69.8%), 26 out of 50 > 25%; median 18.6% (range 0-60.3), 20 out of 50 > 25%, for 1, 2, and 3 cm margins, respectively. The median distance from the scar midpoint to the furthest clip was 3.8 (range 1.2-8.1) cm. The median maximal clip depth was 3.1 (range 1.4-5.2) cm. CONCLUSION: (a) Electron boost field planning by clinical landmarks alone was inaccurate in 68% of cases. (b) Quantitative measures, based on margins of 1, 2, and 3 cm, revealed that in 20-34% of patients more than one-quarter of the clinical field covered tissue at low risk of local recurrence, and in 40-56% of patients less than three-quarters of the final radiological field was predicted clinically. (c) The relative positions of the scar and clips may be widely disparate. (d) Clip depth measurements reveal a significant risk of underdosing at depth.

Breast Neoplasms↗
PubMed1994

Framework for analyzing an ethical problem and conducting an ethical consultation.

Clinical ethics are an intrinsic aspect of practice in health care settings. However, health care professionals may have minimal training in ethics and communication. Clinical ethics committees, with a multidisciplinary composition, are in a position to offer clinical consultative services from a collaborative framework. Using this framework, as well as standard guidelines for conducting an ethics consultation, most often elicits essential beliefs, values, concerns, and opinions pertinent to the case at hand. Through enhancement of the communication process, group consensus is usually achieved. The framework guiding the consultation and communication process is delineated and illustrated through case analysis.

Communication↗
PubMed1989

Transcutaneous electrical nerve stimulation at acupuncture points in the induction of uterine contractions.

The effectiveness of transcutaneous electrical stimulation at acupuncture points for increasing uterine contractions in 20 post-dates pregnant women was assessed in a controlled study. Subjects were randomly assigned to either a treatment condition, consisting of the application via surface electrodes of a 30-Hz current to the points "spleen 6" (lower leg) and "liver 3" (foot), or a placebo condition, in which the equipment was attached but not activated. The frequency and strength of uterine contractions were monitored for 1 hour prior to stimulation and then for the final 2 hours of a 4-hour test period. A significant increase in frequency and strength of uterine contractions was found in the electrically stimulated women compared with the placebo-group women. The possible physiologic mechanisms underlying this effect, and its implication for labor induction, are discussed.

Acupuncture Therapy↗
PubMed1986

Phase I clinical trial of an MAF-containing lymphoblastoid cell line supernatant.

A preliminary Phase I evaluation of macrophage activating factor (MAF) derived from the partially purified supernatant of human RPMI-1788 lymphoblastoid cell line was performed in 4 parts in 39 patients with advanced cancer. The first two parts used subcutaneous routes of administration and the second two parts used a 4-h intravenous infusion method. Individual doses ranged from 0.1 ml (1.7 mg protein) to 100 ml (1,700 mg protein). Subcutaneous dose was limited by the volume of administered material, and an attempt to use a concentrate of the supernatant resulted in severe local skin reactions. Larger doses given intravenously were well tolerated. Resultant toxicity was mild and consisted of transient fever and chills. One patient with malignant melanoma had a complete response of a 3-cm skin metastasis; one patient with breast cancer had disappearance of a skin nodule while visceral disease progressed; and one patient with histiocytic lymphoma had resolution of a conjunctival lesion. Treatment in many patients was associated with an increase in absolute peripheral lymphocytes. In the high-dose intravenous group, a statistically significant increase in the phagocytic index of peripheral blood leukocytes was noted. Lymphoblastoid MAF appears to be relatively safe to administer and has promise both as an antitumor agent and in the treatment of other altered immune conditions.

Adolescent↗
PubMed1983

Lymphokine-stimulated macrophage phagocytosis of fluorescent microspheres: a rapid new assay.

A highly sensitive and rapid in vitro macrophage phagocytosis assay is described for screening of lymphokine preparations with macrophage activating properties. Non-induced mouse peritoneal macrophages were incubated on glass slides for 60 min in the presence of fluorescent 2 micron latex beads and partially purified lymphokine fractions or media control. Lymphokine samples were prepared from culture supernatants of the B lymphoblastoid cell line RPMI 1788 by high performance liquid chromatography of a soluble trichloroacetic acid extract of concentrated culture supernatant. Phagocytosis was measured by direct counts of the percent phagocytic cells and the number of intracellular beads per 100 cells as seen by fluorescence microscopy. Phagocytic uptake in the presence of as little as 0.1 ng of active lymphokine could readily be determined qualitatively by correlation plots and quantitatively by appropriate statistical programs for data processing by computer. This technique provides a rapid, reproducible, screening assay for biological activity of macrophage activating lymphokines and other compounds affecting macrophage phagocytosis.

Animals↗
PubMed1983

Fractionation of whole body irradiation before bone marrow transplantation for patients with leukaemia.

Thirty patients in various stages of acute leukaemia or chronic granulocytic leukaemia (CGL) were treated with cytotoxic drugs followed by whole body irradiation (TBI) administered in 200 cGy fractions twice daily to a total of 1000 or 1200 cGy. The immediate toxicity of fractionated TBI administered in this way was negligible and patients required only minor premedication and little treatment subsequently for complications attributable to TBI. Fourteen (47%) patients have died, ten of the 12 transplanted with active disease, and four of the 18 subjected to transplantation in remission of acute leukaemia or in chronic phase of CGL. Though the duration of follow-up is still short, no patient in the latter group (follow-up of survivors ranging from six to 146 weeks) has yet relapsed with any evidence of recurrent leukaemia. We conclude that this method of fractionating TBI reduced toxicity for the patient without necessarily reducing its antileukaemic effect.

Acute Disease↗
PubMed1981

Quantitation of neutrophil phagocytosis, using fluorescent latex beads. Correlation of microscopy and flow cytometry.

Phagocytic particle uptake was calculated from data obtained by microscopy and flow cytometry utilizing commercially available fluorescent beads of uniform (2 micrometer diameter) size. PMNs collected from a Ficoll-Hypaque density gradient were incubated with the fluorescent beads in human plasma and gently washed in buffer to remove most of the extracellular beads. The cells were observed and analyzed by fluorescence microscopy (sample size = 300 cells) and flow cytometry (sample size = 50,000 cells) to determine the percent phagocytic cells, number of beads per phagocytic cell, and beads per 100 PMNs. Correlation of these indices for microscopic and machine counts was in high agreement, with r values greater than 0.80. Since flow cytometry increases the sample size 500-fold above that attained by manual microscopic counts, the coefficient of variation is proportionately reduced. Unlike other automated techniques for phagocytosis such as the use of radiolabeled particles, flow cytometry yields information on the cell population such as percent of phagocytic cells and the distribution of intracellular fluorescent beads per cell as well as particle uptake. Thus the advantages of speed, greater statistical accuracy, and the ability to accumulate information on the cell population indicate that flow cytofluorometry has unique applications for the study of phagocytosis. Application of the technique to in vitro stimulation of blood neutrophil phagocytic uptake is included.

Cytological Techniques↗
PubMedDate not supplied

Percutaneous umbilical blood sampling.

Percutaneous umbilical blood sampling (PUBS) provides a new and exciting method for assessment and management of certain fetal disorders. This procedure offers direct access to the fetal circulation for obtaining blood samples or for transfusing the fetus in utero. Although investigational, PUBS offers treatment approaches that were not previously available. This ability to treat the fetus in utero can prolong pregnancy, resulting in decreased prematurity and mortality rates for infants with erythroblastosis fetalis. This article describes the PUBS procedure and the indications for PUBS and discusses the nursing implications associated with the care of women undergoing PUBS.

Blood Specimen Collection↗
PubMedDate not supplied

Care of the neonate with erythroblastosis fetalis.

Erythroblastosis fetalis, hemolytic disease of the newborn, occurs when an isoimmunized mother produces antibodies that cross the placenta and cause hemolysis of fetal red blood cells. This hemolysis can be accompanied by severe anemia, ascites, pleural and pericardial effusions, congestive heart failure, and neurological damage with resultant perinatal mortality. Rh isoimmunization in pregnancy still occurs in spite of the advent of Rh immune globulin. This article describes the complex management and nursing implications associated with caring for the neonate with erythroblastosis fetalis.

Anemia, Hemolytic↗
PubMedDate not supplied

Maternal hypothermia: implications for obstetric nurses.

Hypothermia, a core body temperature of less than 95 degrees F (35 degrees C), is a common intraoperative complication among adult patients and may occur in obstetric patients. Obstetric patients are predisposed to hypothermia because of vasodilation from pregnancy, administration of anesthetics and pharmacologic agents, and inherent blood loss with rapid fluid replacement during delivery. Morbidity associated with hypothermia occurs from complications such as hypotension, cardiac arrhythmias, increased oxygen consumption or respiratory depression, and disseminated intravascular coagulation. Interventions include preventive measures such as maintaining reasonable ambient room temperatures, avoiding infusion of cold solutions, and promptly assessing postoperative temperature, as well as corrective measures--rewarming the patient, placing the patient on dry surfaces, minimizing additional heat loss, and providing external heat sources.

Body Temperature Regulation↗
PubMedDate not supplied

Oncofetal fibronectin: new insight into the physiology of implantation and labor.

Oncofetal fibronectin is a newly studied protein produced by the trophoblast and is present in plasma and cervicovaginal secretions of pregnant women as labor approaches or when they have certain complications of pregnancy. Alterations in levels of oncofetal fibronectin occur in preterm labor, postterm pregnancy, and pregnancy-induced hypertension. Determining the presence or absence of full-term and preterm labor often is difficult in the clinical setting, and decision-making sometimes is hindered by the lack of a specific biochemical marker for labor. Oncofetal fibronectin may become a clinical indicator or predictor of true labor, preterm labor, or some complications of pregnancy. Assay techniques that identify clinically meaningful levels of oncofetal fibronectin are being developed and investigated and soon may be available to screen and identify pregnant women at risk. Research findings suggest new paths for investigation that may lead to important interventions in health care directed at identifying and decreasing maternal and neonatal morbidity and mortality. This article reviews pertinent aspects of placentation and the rationale for using oncofetal fibronectin detection as a clinical marker for abnormal pregnancy states.

Adenosine Monophosphate↗
PubMedDate not supplied

Nephropathogenic infectious bronchitis in Pennsylvania chickens 1997-2000.

Nephropathogenic infectious bronchitis (NIB) was diagnosed in 28 infectious bronchitis virus (IBV)-vaccinated commercial chicken flocks in Pennsylvania from December 1997 to July 2000. Early dinical signs were increased flock mortality and urinary water loss (polyuria and pollakiuria) leading to wet litter. Daily mortality ranged from 0.01% in layers to 2.45% in broilers, with total broiler mortality as high as 23%. Severe renal swelling and accumulation of urates in the tubules were commonly seen. Visceral gout and urolithiasis were less frequently observed. Histopathologic changes included characteristic tubular epithelial degeneration and sloughing with lymphoplasmacytic interstitial nephritis. Minimal respiratory disease signs were noted in broilers. Egg production and shell quality declined in layers. Confirmatory diagnosis of NIB was made by IBV antigen-specific immunohistochemical staining of the renal tubular epithelium and virus isolation. Sequencing of the S1 subunit gene of 21 IBV isolates showed the NIB outbreak to be associated with two unique genotypes, PA/Wolgemuth/98 and PA/171/99. The cases from which the genotypes were isolated were clinically indistinguishable. The NIB viruses were unrelated to previously recognized endemic strains in Pennsylvania and were also dissimilar to each other. Genotype PA/Wolgemuth/98 was isolated almost exclusively during the first 14 mo of the outbreak, whereas PA/171/99 was recovered during the final 18 mo. The reason for the apparent replacement of PA/Wolgemuth/98 by PA/171/99 is not known.

Animals↗