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Biomedical subjects

C Pope

Publications and source records attributed to C Pope.

At least 73 records · Page 4Linked to original sources
PubMed1987

Venous clots: evaluation with MR imaging.

In vitro and in vivo studies were performed to determine the proton relaxation and imaging characteristics of static blood and acute and organized clot in canine jugular veins. In vivo, it was found that two inversion recovery sequences using a short inversion time (100 msec) demonstrated better differentiation of signal intensity of intravascular clot from surrounding soft tissues than did standard T1- and T2-weighted sequences. In vitro, quantitative measurements showed marked reduction of both T1 and T2 relaxation time of acute clot compared with stagnant blood. In addition, the T1 relaxation time, and to a lesser extent the T2 relaxation time, shortened as the clot aged, indicating a potential role for magnetic resonance imaging in determining the age of venous thrombi.

Animals↗
PubMed1984

Subjective health assessments and the perceived outcome of minor surgery.

A simple and standardised measure of perceived health status, the Nottingham Health Profile, was used to assess the effect on perceived health status of surgical intervention in a variety of non-acute medical disorders. Patients were assessed a few days before their operation and again two months later and were compared with a control group who had not undergone surgery. Results showed very little change in subjective health from before to after surgical intervention. The experimental group had similar perceived health scores to the control group on the pre- and post-tests. It is suggested that the period allowed to elapse after surgical intervention was too short, or that the level of problems experienced by patients prior to surgery was too low to show significant change. It is also possible that the particular presenting disorders were only one possible somatic representation of general feelings of minor ill-health in the group. The findings of this study point to the need to look at the differences between doctors and patients expectations of the outcome of surgery, the decision to seek care and the factors that govern wellbeing.

Adolescent↗
PubMed1981

Role of viable mycoplasmas in the pathogenesis of arthritis induced by M. pulmonis.

The role of viable M. pulmonis organism in the pathogenesis of both the acute and chronic phases of M. pulmonis-induced arthritis was examined. In the acute phase of the arthritis most clinically involved joints contained organisms and the degree of clinical arthritis in a given joint correlated with the number of organisms isolated. The more severe the acute arthritis, the more frequently the M. pulmonis organism was isolated from the joints during the chronic phase. In the chronic phase, arthritis defined histologically correlated with the presence of M. pulmonis organisms within a given joint. No correlation was observed between clinical arthritis during the chronic phase and histopathology or the presence of M. pulmonis organisms within the joint. In chronically infected mice, M. pulmonis was isolated from the joints only but not from the blood, liver, spleen, lung or kidney of any mouse examined. The results support the concept that viable organisms play an essential role in the pathogenesis of the acute and chronic phases of M. pulmonis-induced arthritis in mice.

Animals↗
PubMed1981

Enhanced resistance of mice to Mycoplasma pulmonis-induced arthritis by administration of killed Corynebacterium parvum.

Inoculation of mice with Corynebacterium parvum 14 days before intraperitoneal inoculation of Mycoplasma pulmonis resulted in arthritis of significantly lesser magnitude than in control mice as measured both clinically and histologically. Mycoplasmas were isolated from the joints of mice inoculated with C. parvum less frequently than from control mice when the arthritis was maximal. Mycoplasmas were also isolated in smaller numbers from the blood and joints of mice pretreated with C. parvum within 2 hr after M. pulmonis inoculation. Complement-fixing antibody to M. pulmonis did not account for the differences observed. C. parvum given during an established mycoplasmal infection, although capable of enhancing elimination of M. pulmonis from the joints of infected mice, had no effect upon the arthritis as measured clinically or histologically. The results provide evidence that immunomodulators such as C. parvum are capable of enhancing elimination of mycoplasmas from the joints of infected mice prior to or after the induction of arthritis.

Animals↗
PubMed1980

Effect of T-cell deficiency on the chronicity of arthritis induced in mice by Mycoplasma pulmonis.

Mycoplasma pulmonis inoculated parenterally into athymic nude mice congenitally deficient in T cells caused a chronic arthritis of significantly greater magnitude than in immunologically normal mice. During the chronic phase of arthritis, M. pulmonis organisms were isolated from the joints and spleens of athymic nude mice more frequently and in larger numbers than from immunologically normal mice. The results support the concept that impaired T-cell function predisposes the mice to a severe degree of chronic arthritis as a result of their failure to eliminate the causative organisms.

Animals↗
PubMed1979

Two dimensional echocardiographic characteristics of double outlet right ventricle.

The reliability was evaluated of two dimensional echocardiography in distinguishing double outlet right ventricle from other anomalies of the great arteries. Accordingly, a combined retrospective and prospective study was conducted in 13 children with double outlet right ventricle, 12 with tetralogy of Fallot, 13 with complete d-transposition of the great arteries, 5 with congenitally corrected I-transposition and 2 with truncus arteriosus. Echographic findings using a standard long axis view in all subjects with double outlet right ventricle included (1) inability to identify a great artery arising from the left ventricle, and (2) lack of continuity between the anterior mitral leaflet and any semilunar valve. In the short axis view constant findings were (1) simultaneous imaging of both great arteries in an anterior location with the ventricular septum identified posteriorly on sweeping into the left ventricle, and (2) lack of a clockwise wraparound of the aorta by the right ventricular outflow tract. Imaging revealed that the great arteries were side by side in seven patients d-malposed in three and l-malposed in two. A modified left precordial tomographic view demonstrated both great arteries arising from the right ventricle in four of nine patients not treated surgically. In four patients with surgically repaired double outlet right ventricle, the left ventricular outflow tract had a tunnel-like configuration in the long axis view. These findings were diagnostic of double outlet right ventricle in all patients and accurately differentiated the malformation from other anomalies of the great arteries.

Adolescent↗
PubMedDate not supplied

Zymosan-induced arthritis: a model of chronic proliferative arthritis following activation of the alternative pathway of complement.

Zymosan particles, which are able to activate complement by the alternative pathway and to induce enzyme secretion from macrophages, were injected into knee joints of mice. After various time intervals, synovia were assessed histologically for various markers of inflammation. Within 7 days after intraarticular injection of zymosan, a chronic inflammatory arthritis with mononuclear cell infiltration, synovial hypertrophy and pannus formation was observed. Latex particles, which do not activate complement or macrophages, produced only mild, transient inflammatory reactions.

Animals↗
PubMedDate not supplied

Effect of inherited deficiency of the fifth component of complement on arthritis induced in mice by Mycoplasma pulmonis.

Mycoplasma pulmonis inoculated parenterally into mice deficient in the fifth component of complement (C5) caused a chronic arthritis of significantly greater magnitude than in immunologically normal mice. During the chronic phase of arthritis M pulmonis organisms were isolated from the joints and organs of C5 deficient mice more frequently and in larger numbers than from immunologically normal mice. The implications of the results are discussed in relation to the pathogenesis of M pulmonis induced arthritis and human connective tissue diseases.

Animals↗
PubMedDate not supplied

Heterogeneous signal intensity in magnetic resonance images of hypertrophied left ventricular myocardium.

Left ventricular hypertrophy is associated with decreased longevity and often leads to congestive heart failure. An exploratory study of magnetic resonance imaging in human left ventricular hypertrophy was performed. First, 13 patients with left ventricular hypertrophy and 7 controls of similar ages were studied using electrocardiogramgated end-diastolic images. Visual inspection suggested that low-intensity zones were frequently found within the hypertrophied myocardium. To verify this observation, the images were processed with semi-automatic edge detection and a derivative-based tissue characterization algorithm, yielding tissue heterogeneity indices (THI-A and THI-V) which objectively measured the low-intensity zones. THI-A and THI-V were both significantly greater in left ventricular hypertrophy patients than in controls (THI-A: 0.111 vs 0.038, p = 0.009). THI was also significantly correlated with duration of disease and electrocardiographic abnormalities. To validate these initial findings prospectively, the same quantitative analysis was applied to magnetic resonance images of an additional 20 left ventricular hypertrophy patients and 12 controls from two institutions, using different imaging systems and different acquisition parameters. Again, THI was significantly greater in patients than in controls. Analysis of end-systolic images yielded similar results. In four dogs with left ventricular hypertrophy induced by aortic banding, THI showed a statistically significant increase as left ventricular hypertrophy developed. Hypertrophied myocardium thus shows reproducible differences from normal tissue with magnetic resonance imaging; hence, quantitative magnetic resonance tissue characterization may be useful in assessing pathologic changes in LVH.

Adult↗
PubMedDate not supplied

Extended storage of platelets in a new plastic container. II. In vivo response to infusion of platelets stored for 5 days.

A new blood container material (PL 1240 plastic) made of polyvinyl chloride containing a tri(2-ethylhexyl) trimellitate plasticizer was evaluated in three laboratories. When platelet concentrates (50-60 ml) were stored on a variety of agitators for 7 days at 22 +/- 2 degrees C, poststorage pH (mean +/- SD) ranged from 7.29 +/- 0.05 (6 rpm elliptical rotator) to 6.87 +/- 0.8 (70 cycles per minute flatbed agitator). The platelet counts ranged from 1.51 +/- 0.12 to 0.95 +/- 0.36 X 10(6) per microliter. Morphology scores and hypotonic shock response values of platelets stored 7 days in PL 1240 plastic containers were better than those noted following 3-day storage of control platelets in PL 146 plastic containers. The percent discharge of lactic dehydrogenase from platelets stored 7 days in PL 1240 plastic containers for 3 days (p less than 0.05). Mean platelet recoveries of 44 +/- 15 percent (n = 11; 111Indium) and 39 +/- 8 percent (n = 29; 51Chromium) were seen when autologous platelets were infused following 5-day storage in PL 1240 plastic bags. Platelet half-lives of 3.6 +/- 0.4 (n = 9) 4.1 +/- 0.4 (n = 20) days were reported in the two laboratories which used 51Cr labeling, while survival values of 7.0 +/- 1.0, 2.8 +/- 0.8, and 5.4 +/- 1.9 days were seen when data from the 111Indium studies (n = 11) were analyzed using linear, exponential, and multiple hit programs, respectively. Platelets stored for 5 days also were administered to 13 thrombocytopenic oncology patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Platelets↗
PubMedDate not supplied

The effect of mode of agitation and type of plastic bag on storage characteristics and in vivo kinetics of platelet concentrates.

We studied the characteristics of platelet concentrates stored for 5 days at 22 degrees C. Platelets were prepared in three plastic bags (PL 732, PL 1240, and CLX) and stored on one of four platelet agitators, 1- or 6-rpm elliptical and 2- or 6-rpm circular rotators. A total of 76 studies were divided among 12 groups, each group being composed of a different storage bag-rotator combination. In vivo recovery and survival were calculated using Indium-111 oxine-labeled platelets injected into autologous volunteers. Platelet recovery was assessed at 2 hours postinjection or as the y-intercept of the multiple-hit model survival curve. Survival was calculated using linear, exponential, and multiple-hit computer models. Linear T 1/2 also was calculated as an index of platelet survival. At 5 days, the pH of all concentrates was above pH 7.0 and platelet counts were above 5.5 X 10(10) per bag except for the PL 732 with the 6-rpm elliptical rotator, which was 4.6 X 10(10) per bag. This combination also showed a significantly higher poststorage lactic dehydrogenase (LDH) discharge compared to the mean of the other 11 groups (23.6 +/- 5.4% vs. 10.4 +/- 3.0%, p less than 0.05); however, the beta-thromboglobulin (beta-TG) release was not statistically different.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Donors↗