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Biomedical subjects

C Quinn

Publications and source records attributed to C Quinn.

At least 37 records · Page 2Linked to original sources
PubMed1998

Use of bilevel positive airway pressure (BIPAP) in end-stage patients with cystic fibrosis awaiting lung transplantation.

Nine consecutive end-stage patients with cystic fibrosis (CF) awaiting lung transplantation were admitted to the pediatric intensive care unit (PICU) in respiratory decompensation. They all received noninvasive bilevel positive airway pressure (BIPAP) support and were evaluated to determine whether or not it improved their oxygenation and provided them with long-term respiratory stability. BIPAP was applied to all patients after a brief period of assessment of their respiratory status. Inspiratory and expiratory positive airway pressures (IPAP, EPAP) were initially set at 8 and 4 cm H2O respectively. IPAP was increased by increments of 2 cm H2O and EPAP was increased by 1 cm H2O increments until respiratory comfort was achieved and substantiated by noninvasive monitoring. Patients were observed in the PICU for 48 to 72 hours and then discharged to home with instructions to apply BIPAP during night sleep and whenever subjectively required. Regular follow-up visits were scheduled through the hospital-based CF clinic. The patients' final IPAP and EPAP settings ranged from 14 to 18 cm H2O and 4 to 8 cm H2O, respectively. All nine patients showed a marked improvement in their respiratory status with nocturnal use of BIPAP at the time of discharge from the PICU. Their oxygen requirement dropped from a mean of 4.6 +/- 1.1 L/min to 2.3 +/- 1.5 L/min (P < 0.05). Their mean respiratory rate decreased from 34 +/- 4 to 28 +/- 5 breaths per minute (P < 0.05). The oxygen saturation of hemoglobin measured by pulse oximetry, significantly increased from a mean of 80% +/- 15% to 91% +/- 5% (P < 0.05). The patients have been followed up for a period of 2 to 43 months and have all tolerated the use of home nocturnal BIPAP without any reported discomfort. Six patients underwent successful lung transplantation after having utilized nocturnal BIPAP for 2, 6, 14, 15, 26, and 43 months, respectively. Three patients have utilized home BIPAP support for 2, 3, and 19 months, respectively, and continue to await lung transplantation. An acute development of refractory respiratory failure resulted in the demise of the remaining three patients after having utilized BIPAP for 3, 6, and 10 months, respectively. The authors conclude that BIPAP therapy improves the respiratory status of decompensating end-stage CF patients. It is well tolerated for long-term home use and provides an extended period of respiratory comfort and stability for CF patients awaiting lung transplantation.

Adult↗
PubMed1998

Auricular acupuncture as an adjunctive treatment for cocaine addiction. A pilot study.

The authors conducted a single-blind study of auricular acupuncture in 36 cocaine-dependent inpatient veterans on a substance abuse treatment unit to determine whether the treatment could help reduce craving, increase treatment retention, and prevent relapse. Acupuncture was given on a predetermined schedule to both treatment and control groups, with status assessed regularly by independent, blinded raters. The study failed to show a significant difference between treatment and control groups. However, the study patients, as a whole, did remain in treatment longer than a retrospectively analyzed group who received no acupuncture.

Acupuncture Therapy↗
PubMed1997

Nuclear localization of RelB is associated with effective antigen-presenting cell function.

Dendritic cells (DC) are potent APCs that enter resting tissues as precursors and, after Ag exposure, differentiate and migrate to draining lymph nodes. The phenotype of RelB knockout mice implicates this member of the NF kappa B/Rel family in DC differentiation. To further elucidate the role of RelB in DC differentiation, mRNA, intracellular protein expression, and DNA binding activity of RelB were examined in immature and differentiated human DC, as well as other PB mononuclear cell populations. RelB protein and mRNA were detected constitutively in lymphocytes and in activated monocytes, differentiated DC, and monocyte-derived DC. Immunohistochemical staining demonstrated RelB within the differentiated lymph node interdigitating DC and follicular DC, but not undifferentiated DC in normal skin. Active nuclear RelB was detected by supershift assay only in differentiated DC derived from either PB precursors or monocytes and in activated B cells. These RelB+ APC were potent stimulators of the MLR. The data indicate that RelB expression is regulated both transcriptionally and post-translationally in myeloid cells. Within the nucleus, RelB may specifically transactivate genes that are critical for APC function.

Adult↗
PubMed1997

The effects of intravenous anesthetics on intracranial pressure and cerebral perfusion pressure in two feline models of brain edema.

PURPOSE: The purpose of this study was to investigate the effects of various intravenous anesthetics on intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in two models of brain edema in a prospective study in a Pediatric critical care animal laboratory in a university hospital. MATERIALS AND METHODS: Intraparenchymal ICP monitors were inserted in 30 anesthetized adult cats. In 15 cats, an intraparenchymal balloon-tipped catheter was placed and inflated to create a space-occupying lesion (SOL) to mimic vasogenic brain edema (VBE). In the other 15 cats, cytotoxic brain edema (CBE) was created by an acute reduction in blood osmolality. We used continuous hemodiafiltration (CAVH-D) and replaced the ultrafiltrate with hypotonic solution to maintain euvolemia. At predetermined points, each cat in each model received multiple intravenous (i.v.) injections of one of the following medications: methohexital 1.5 mg/kg, propofol 2 mg/kg, or ketamine 2 mg/kg. ICP and mean arterial pressure (MAP) were continuously monitored in all animals. RESULTS: In the SOL model, all three anesthetic agents decreased ICP after each administration (P < .05). Ketamine administration also resulted in an increase in CPP in this model (P < .05). In the CBE model, none of these agents resulted in a significant change in either ICP or CPP. CONCLUSIONS: Our results indicate that i.v. anesthetics decrease ICP caused by SOL but have no significant effect on ICP due to CBE. We postulate that in the SOL model, and similarly in VBE, some brain tissue is viable and remains responsive to anesthetics. In contrast, in the CBE model, diffuse intracellular damage occurs, the cerebral metabolic rate may be severely depressed, autoregulation of the cerebral vasculature may be impaired, and unresponsiveness to i.v. anesthetics may occur.

Analysis of Variance↗
PubMed1997

Monitoring interactions between spontaneous respiration and mechanical inflations in preterm neonates.

OBJECTIVES: To determine the value of a new bedside monitor in assessing the interactions between spontaneous respiratory activity and ventilator inflations in preterm infants; and to monitor continuously the degree of patient-ventilator synchrony and the stability of spontaneous respiratory effort during different modes of ventilation and in response to care procedures. DESIGN: A prospective, observational study of physiologic variables recorded by a computerized monitoring system. SETTING: A neonatal intensive care unit in a teaching hospital. PATIENTS: Thirty-one neonates (median gestational age of 28 wks [range 24 to 36]; median birth weight of 942 g [range 624 to 2940]) were monitored during conventional mandatory ventilation at rates ranging from 47 to 108 inflations/min, and 22 infants (median gestational age of 27.5 wks [range 25 to 40]; median birth weight of 1345 g [range 510 to 3490]) were monitored during patient-triggered ventilation. All infants were sedated as part of the routine care policy. INTERVENTIONS: Spontaneous respiration (abdominal pressure capsule) and ventilator inflations (airway pressure) were recorded continuously for periods of up to 3 days in mechanically ventilated preterm infants. MEASUREMENTS AND MAIN RESULTS: The monitoring system uses the Frequency Tracking Locus method to derive the interaction Score, which quantifies the degree of entrainment of the spontaneous respiratory pattern by the ventilator. This analysis was applied to airway pressure and abdominal capsule signals. A perfect 1:1 interaction between spontaneous inspirations and mechanical inflations returns an interaction Score of 1.00, and irregular interactions return a score of > 1.5. During conventional mandatory ventilation, a total of 53,074 16-sec epochs (representing 782,811 spontaneous breaths) were studied in 31 preterm infants: 27.4% of epochs showed a 1:1 interaction, 60.5% a non 1:1 interaction, and 12.1% indicated a passive (i.e., infant apneic) response by the infant, despite excluding periods when paralyzing agents were used. The median interaction Score value during 1:1 interactions was 1.2, whereas for non 1:1 interactions the interaction Score was 2.2. One to one entrainment occurred at conventional mandatory ventilation rates between 50 and 85 inflations/min: for many infants, such entrainment was achievable over a range of conventional mandatory ventilation rates, while in some infants respiration was unstable at all rates of conventional mandatory ventilation. During passive ventilation, the median Interaction Score was 1.0. During patient-triggered mechanical ventilation, approximately 67,150 spontaneous respiratory cycles, represented by 3,592 16-sec epochs, were studied in 22 infants. Overall, 19.5% (702) of epochs showed the criteria for ideal triggering by spontaneous inspiration and 19.6% (703) showed autotriggering. In 60.9% (2187) of epochs, a non 1:1 interaction was noted. During ideal patient-triggered mechanical ventilation, the median interaction Score was 1.14; during passive (autotriggered) ventilation, the median Interaction Score was 1.05; and during non 1:1 ventilation, the median score was 1.74. "Autotriggering" was found frequently in infants of < or = 28 wks gestation. The monitor was able to distinguish between stable and unstable interactions and apnea during conventional mandatory ventilation and patient-triggered mechanical ventilation by reference to the Interaction Score value. CONCLUSIONS: We describe a new kind of bedside monitor for the Interpretation of respiratory data. Unlike other methods, it is able to give the clinician a continuous measure of patient-ventilator interaction which is easy to interpret. It appears to have wide-spread application in neonatal intensive care nurseries where the babies' own breathing efforts can affect the efficiency of respiration and cause unwanted physiologic instability. The monitor can be used to determine the optimal ventilatory settings to

Humans↗
PubMed1997

Increased artificial deadspace ventilation is a safe and reliable method for deliberate hypercapnia.

OBJECTIVES: To develop a simple method in an animal model to achieve deliberate hypercapnia, which can be used easily and safely to regulate the pulmonary vascular resistance without changing mean airway pressure and compromising oxygenation. DESIGN: Prospective study, with each animal used as its own control. SUBJECTS: Minipigs, weighing 11 to 14 kg (n = 7). INTERVENTIONS: A quadrilumen thermodilution pulmonary artery catheter was placed in minipigs via the internal jugular vein. Systemic blood pressure was measured with use of a femoral arterial catheter. The animals' lungs were ventilated with an FIO2 of 1.0, and a stable state of eucapnia was achieved and maintained for 30 mins. The artificial deadspace was increased every 30 mins, by connecting 45-mL (3- to 4-mL/kg) corrugated tube segments until a total deadspace volume of 180 mL was added. MEASUREMENTS AND MAIN RESULTS: Hemodynamic performance was evaluated at baseline and after 45 mL (3 to 4 mL/kg), 90 mL (6 to 8 mL/kg), 135 mL (9 to 11 mL/kg), and 180 mL (12 to 15 mL/kg) of added deadspace. Data were indexed to the animal's weight (in kg). Increased artificial deadspace produced a significant (p < .05) increase in PaCO2. These increases in PaCO2 were associated with significant (p < .05) increases of 23%, 32%, 45%, and 46% in the mean pulmonary vascular resistance values, and 6%, 16%, 23%, and 23% in the mean pulmonary arterial pressure, respectively. The systemic pH was decreased from a mean baseline value of 7.45 to 7.39, 7.28, 7.20, and 7.11, respectively. There were no significant changes in PaO2, oxygen consumption, systemic vascular resistance, and cardiac output throughout the experiments. CONCLUSIONS: A gradual increase in artificial deadspace ventilation produces a state of deliberate hypercapnia. In our animal model, a moderate increase in artificial deadspace significantly increased the pulmonary vascular resistance but was not associated with detrimental respiratory acidemia. Larger volumes of added artificial deadspace had no detrimental effect on cardiac output, oxygen content, oxygen consumption, and systemic vascular resistance, but were associated with significant respiratory acidemia and therefore should be avoided.

Acidosis, Respiratory↗
PubMed1997

Screening for ocular hemorrhages in patients with ruptured cerebral aneurysms: a prospective study of 99 patients.

BACKGROUND: Terson's syndrome (vitreous hemorrhage) and other ocular hemorrhages (retinal hemorrhages) have been reported to occur in up to 40% of patients with ruptured cerebral aneurysms. Because microsurgical vitrectomy can safely restore vision in patients with visual loss secondary to Terson's syndrome, we hypothesized that prospectively screening a selected group of patients with aneurysms would result in a higher rate of vitrectomy in patients with more extensive subarachnoid hemorrhage. METHODS: Ninety-nine patients with ruptured cerebral aneurysms were prospectively screened for Terson's syndrome and other forms of ocular hemorrhage by an ophthalmologist. Follow-up data were obtained for seven of eight cases of Terson's syndrome, and vitrectomy was performed for visual restoration when indicated. RESULTS: Ocular hemorrhages were present in 17% of patients with ruptured cerebral aneurysms, and Terson's syndrome was present in 8% of patients. Screening of patients with histories of transient or prolonged comas sensitively identified patients with ocular hemorrhages in 100% of the patients with Terson's syndrome and 89% of the patients with other ocular hemorrhages. Fifty-five percent of the patients in the overall series had histories of transient or prolonged comas, and 53% (specificity) of those patients had ocular hemorrhages. Two of the eight patients with Terson's syndrome underwent vitrectomy, with dramatic improvement in vision. No other ocular hemorrhages required surgery. CONCLUSIONS: Ophthalmological screening of patients with histories of transient or prolonged comas after ruptured cerebral aneurysms very sensitively identifies patients with ocular hemorrhages, which are relatively common in patients with subarachnoid hemorrhage treated in an academic neurosurgical practice. The present study underestimates the true incidence of Terson's syndrome in that patients who died shortly after their subarachnoid hemorrhage were not included. Vitrectomy for patients who do not exhibit spontaneous improvement in vision results in a dramatic reversal of blindness.

Adult↗
PubMed1997

Issues of medical necessity: a medical director's guide to good faith adjudication.

The term medical necessity is difficult to define, a problem for insurers who need to clearly describe what is and is not covered in their contracts with subscribers. An unclear, vague definition of medical necessity leaves insurers vulnerable to litigation by subscribers denied care deemed medically unnecessary. To avoid lawsuits, insurers must make every effort to educate their subscribers about their medical coverage, going beyond merely providing a lengthy subscriber handbook. In decisions on medical necessity, medical directors at insurance companies play a key role. They can bolster the insurer's position in denial-of-care cases in numerous ways, including keeping meticulous records, eliminating unreasonable financial incentives, maintaining a claims denial database, and consulting with other insurers to achieve a consensus on medical necessity.

Decision Making, Organizational↗
PubMed1997

The DHA.

Explore the source record for details and available documents.

Dental Assistants↗
PubMed1996

Functional differentiation of dendritic cells in rheumatoid arthritis: role of CD86 in the synovium.

Dendritic cells (DC) are the major APC in human peripheral blood (PB) and rheumatoid synovium. We previously identified in PB a population of CD33dim-CD14dim DC precursors, as well as a smaller population of CD33bright CD14dim mature DC. Neither PB DC population expressed the CD28/CTLA4 ligands, suggesting that additional signals are required for full functional DC differentiation. Because rheumatoid synovium is characterized by an ongoing immune response, the expression and function of CD80, CD86, and other markers of DC differentiation by rheumatoid arthritis synovial APC were examined. The phenotype of a large subset of freshly isolated rheumatoid arthritis synovial fluid (SF) DC resembled that of the mature PB DC. These DC expressed CD45R0, CD11c, CMRF-44, and high levels of CD33. Whereas CD80 expression by rheumatoid SF DC and monocytes was minimal, CD86 was expressed by a subset of SF monocytes and by CMRF-44+SF DC. Furthermore, sorted CD86- SF DC spontaneously up-regulated CD86 in vitro. CD80 was expressed diffusely and at low levels by rheumatoid synovial tissue cells, whereas CD86 was expressed by perivascular HLA-DR+HLA-DQ+CD80+CMRF-44+ DC, and by some CD14+ monocytes. Anti-CD86 mAb and CTLA4 Ig, but not anti-CD80 mAb, inhibited the MLR stimulated by SF DC. Both CMRF-44+ and CMRF-44- SF DC were efficient stimulators of the allogeneic MLR, which was in each case blocked by CTLA4 Ig. The data indicate that rheumatoid synovial DC can undergo full functional differentiation, associated with CD86 expression, in vitro and in situ. Synovial DC expressing high levels of MHC molecules and CD86 are strategically located to present arthritogenic Ag to T cells after transendothelial migration.

Antigen-Presenting Cells↗
PubMed1996

The self-management of psychiatric medications: a pilot study.

This paper reports on a pilot study where a scheme for the self-management of medication has been devised as an intervention strategy, where the mental health nurse and the mentally ill client work together to improve the client's knowledge of prescribed medication and medication-related issues. Aspects of non-compliance and the various factors involved in the non-compliance of psychiatric medications by the person who is severely mentally ill are discussed. When non-compliance to psychiatric medication is briefly examined, the complexity of the phenomena becomes increasingly apparent, confounding single intervention strategies, therefore as the phenomena is multidimensional, so must by any response. A review of the literature, and from the past clinical experience of the authors, suggests that when there is an involved therapeutic alliance, and the active participation of both the client and the mental health nurse in a rehabilitation orientated self-medication management scheme, a difference can occur for the client where their understanding of, and compliance with, psychiatric medication can improve. This could possibly improve the overall quality of life for the mentally ill person. Within a psychosocial rehabilitation setting, a self-medication management scheme has been developed that gradually facilitates the client's responsibility for managing their own prescribed medication, and in conjunction with this increased awareness of their medication and related issues, the focus eventually leads to the client having complete responsibility for managing their own medication. This self-medication management scheme consists of several graded stages that are contractual in nature, in which the clients and nurses are active participants. A rating and self-reporting scale has been developed within the scheme and is used by both the nurse and the client to assist in gauging the client's understanding and knowledge of issues related to their medication use. This self-medication management scheme has demonstrated that when severely mentally ill persons are given the opportunity to practice and manage their own medication as a component of the rehabilitative process, a self-medication management scheme does make a difference.

Humans↗
PubMed1996

Defining collegiality within the academic setting.

Faculty development and performance are important issues within colleges of nursing. Collegiality is a performance requirement for promotion and tenure, but the behaviors synonymous with collegiality are frequently unwritten within the academic community as well as being poorly defined in the literature. The ambiguity that this situation produces is often experienced by faculty seeking tenure and promotion. Faculty at a midwestern university used the Delphi technique to determine behaviors synonymous with collegiality. Results of the Delphi rounds yielded specific behavioral indicators for the four broad statements that describe collegiality in the governance document of the university. Those statements include willingness to serve on committees and perform work necessary to departmental operations, willingness to provide guidance and help colleagues in their professional duties, respect for the ideas of others, and conduct of one's professional life without prejudice toward others. Findings revealed that while the area of collegiality is ambiguous, indicators of collegial behavior can be identified. Limitations and benefits of using the Delphi technique are discussed.

Career Mobility↗
PubMed1995

Protection of xenogeneic cardiac endothelium from human complement by expression of CD59 or DAF in transgenic mice.

We investigated the ability of membrane-bound human complement regulatory proteins to control complement-driven humoral immune reactions on murine microvasculature. The human complement regulatory proteins CD59 and DAF were expressed using heterologous promoters in a variety of tissues in transgenic mice. Animals expressing these gene products are healthy and exhibit significant levels of endothelial cell expression of CD59 and DAF in cardiac muscle. Transgenic hearts perfused with human plasma exhibited profound reductions in the level of complement deposition compared with nontransgenic controls. We have also produced transgenic pigs that express these two human genes. Our results indicate that expression of complement regulatory proteins can control activation of complement and suggest that these proteins may have therapeutic applications in some inflammatory diseases and in the development of xenogeneic organs for human transplantation.

Animals↗