PubMed Health⌕ Search

Biomedical subjects

C S Campbell

Publications and source records attributed to C S Campbell.

At least 19 recordsLinked to original sources
PubMed1998

Treatment of mediastinitis: early modified Robicsek closure and pectoralis major advancement flaps.

BACKGROUND: The treatment of sternal wound complications is controversial. It is our practice to combine early aggressive debridement, a modified Robicsek sternal closure, and bilateral pectoralis major advancement flaps with or without closed irrigation in a single procedure. We reviewed our experience to determine the efficacy of this approach. METHODS: Grade II to IV mediastinitis (dehiscence and infection) developed in 47 patients 3 to 14 days after routine open heart operations between 1990 and 1995. Culture-positive infection was identified in 60% (n = 28); 62% (n = 29) had septicemia. Thirty patients underwent incision, drainage, and surgical assessment of the wound. Once systemic signs of infection were under control (no pyrexia, normal white blood cell count), formal single-stage debridement of all infected soft tissues and bones was performed. Sternal stability was achieved using a modified Robicsek closure and bilateral pectoralis major advancement flaps. Seventeen patients were treated with staged procedures. RESULTS: Early sternal closure and coverage with pectoralis major advancement flaps can be associated with a low mortality (0%), low morbidity (13%; n = 4: three superficial wound infections, one seroma), and shortened hospital stay (median, 22 days, compared with a median of 82 days in patients managed with conservative staged treatment; p < 0.05). Sternal stability with excellent functional and aesthetic results has been achieved in all patients. CONCLUSIONS: The combination of aggressive early surgical debridement, sternal closure, and the placement of bilateral pectoralis major advancement flaps is a simple procedure associated with a low mortality and morbidity and a short hospital stay.

Adult↗
PubMed1997

Significance of raised natriuretic peptides after bicaval and standard cardiac transplantation.

BACKGROUND: High levels of plasma atrial natriuretic peptide (ANP) and ventricular natriuretic peptide (BNP) have been identified after standard orthotopic cardiac transplantation. It has been postulated that the high ANP levels are a result of persistent secretion from the large residual atrial mass after transplantation. This study was undertaken to investigate the significance of raised ANP and BNP levels after standard and bicaval orthotopic heart transplantation. METHODS: Plasma ANP and BNP levels were measured in 40 ambulatory, randomly selected cardiac transplant patients (group A, n = 20 had bicaval transplantation; group B, n = 20 had standard transplantation) and 10 healthy volunteers (group C). Cardiac transplant patients underwent endomyocardial biopsy and hemodynamic evaluation. RESULTS: Plasma levels of ANP and BNP were elevated in the transplant recipients in comparison with normal volunteers (p = 0.0001 and p < 0.0001, respectively). There was no significant difference in the ANP levels between group A and group B, whereas BNP levels were higher in group B compared with group A (p = 0.03). Linear regression analysis showed that a faster heart rate, high mean pulmonary artery pressure, high pulmonary capillary wedge pressure, and high transpulmonary gradient were associated with higher levels of BNP (p < 0.05). Lower mean systemic pressure was associated with higher levels of ANP (p < 0.05). CONCLUSIONS: High levels of ANP and BNP are synthesized and secreted by the transplanted denervated human heart regardless of the surgical technique. The level of BNP correlates with ventricular performance and afterload. The bicaval technique seems to be associated with better left ventricular and right ventricular diastolic performance.

Adult↗
PubMed1997

Perception of visible speech: influence of spatial quantization.

Visible speech reading was studied to determine which features are functional and to test several models of pattern recognition. Nine test syllables differing in their initial consonant were presented in intact form or under various levels of spatial quantization. Performance decreased in increasing quantization but remained relatively good at moderate levels of degradation. Different models were tested against the confusion matrices. Six features were identified as functional in distinguishing among the nine consonant--vowel syllables. These features were used as sources of information in a fuzzy-logical model of perception and an additive model. The fuzzy-logical model provided a significantly better description of the confusion matrices, showing that speech reading is analogous to other domains of pattern recognition such as face recognition and facial-affect perception.

Computer Graphics↗
PubMed1997

Persistent nuclear ribosomal DNA sequence polymorphism in the Amelanchier agamic complex (Rosaceae).

Individual plants of several Amelanchier taxa contain many polymorphic nucleotide sites in the internal transcribed spacers (ITS) of nuclear ribosomal DNA (nrDNA). This polymorphism is unusual because it is not recent in origin and thus has resisted homogenization by concerted evolution. Amelanchier ITS sequence polymorphism is hypothesized to be the result of gene flow between two major North American clades resolved by phylogenetic analysis of ITS sequences. Western North American species plus A. humilis and A. sanguinea of eastern North America form one clade (A), and the remaining eastern North American Amelanchier make up clade B. Five eastern North American taxa are polymorphic at many of the nucleotide sites where clades A and B have diverged and are thought to be of hybrid origin, with A. humilis or A. sanguinea as one parent and various members of clade B as the other parent. Morphological evidence suggests that A. humilis is one of the parents of one of the polymorphic taxa, a microspecies that we refer to informally as A. "erecta." Sequences of 21 cloned copies of the ITS1-5.8S gene-ITS2 region from one A. "erecta" individual are identical to A. humilis sequence or to the clade B consensus sequence, or they are apparent recombinants of A. humilis and clade B ITS repeats. Amelanchier "erecta" and another polymorphic taxon are suspected to be relatively old because both grow several hundred kilometers beyond the range of one of their parents. ITS sequence polymorphisms have apparently persisted in these two taxa perhaps because of polyploidy and/or agamospermy (asexual seed production), which are prevalent in the genus.

Base Sequence↗
PubMed1997

Family and employment status associated with women's criminal behavior.

Exploring the relationship between women's criminal behavior as evidenced in violence, type of crime, prior criminal history, and the fulfillment of traditional female roles delineated by marital status, employment status, or presence of children in the home of the woman was based on the evaluation of 141 female inmates, which indicated a limited relationship between fulfilling traditional female roles and the nature of female criminal activity. Married and previously married subjects tended to be involved primarily with murder and secondarily with theft. Single subjects were involved primarily with theft and secondarily involved with robbery. Employed subjects were more likely to be involved with theft and nonviolent crime. Unemployed subjects were more likely to be involved in violent crimes.

Adolescent↗
PubMed1996

Severe mitral valve dysfunction due to unsuspected granulomatous myocarditis: successful cardiac transplantation following attempted mitral valve repair.

Granulomatous involvement of the myocardium is a rapidly fatal disease of uncertain aetiology rarely diagnosed premorbidly. We report a patient who presented with mitral valve incompetence and congestive cardiac failure who underwent a successful mitral valve repair but could not be weaned from cardiopulmonary bypass. Urgent heart transplantation was successfully performed and histological studies of the explanted heart revealed granulomatous myocarditis involving the mitral subvalvular apparatus. Endomyocardial biopsy may be necessary in young patients presenting with mitral valve disease of unknown aetiology.

Adult↗
PubMed1996

Fluid dynamics of a partially collapsible stenosis in a flow model of the coronary circulation.

The influence of passive vasomotion on the pressure drop-flow (delta P-Q) characteristics of a partially compliant stenosis was studied in an in vitro model of the coronary circulation. Twelve stenosis models of different severities (50 to 90 percent area reduction) and degrees of flexible wall (0 to 1/2 of the wall circumference) were inserted into thin-walled latex tubing and pressure and flow data were collected during simulated cardiac cycles. In general, the pressure drop increased with increasing fraction of flexible wall for a given flow rate and stenosis severity. The magnitude of this effect was directly dependent upon the underlying stenosis severity. The diastolic delta P-Q relationship of severe, compliant models exhibited features of partial collapse with an increase in pressure drop at a decreasing flow rate. It is concluded that passive vasomotion of a normal wall segment at an eccentric stenosis in response to periodic changes in intraluminal pressure causes dimensional changes in the residual lumen area which can strongly affect the hemodynamic characteristics of the stenosis during the cardiac cycle. This mechanism may have important implications for the onset of plaque fracture and the prediction of the functional significance of a coronary stenosis based on quantitative angiogram analysis.

Compliance↗
PubMed1996

Orthotopic heart transplantation hemodynamics: does atrial preservation improve cardiac output after transplantation?

BACKGROUND: We have described an alternative technique for orthotopic heart transplantation (bicaval Wythenshawe technique) which maintains the right and left atrial anatomy and contractility. METHODS: Fifty patients were randomized into two groups: group A (n = 25) who had orthotopic heart transplantation using the bicaval Wythenshawe technique and group B (n = 25) who had conventional (Lower and Shumway) technique of orthotopic heart transplantation. We compared the cardiac output (measured by thermodilution technique) with atrial activation (AAI pacing) to cardiac output without atrial activity (VVI pacing) in both groups to identify any beneficial hemodynamic effects. All patients were studied the first and second weeks after transplantation. The inaccuracies of comparing cardiac output measurements caused by different loading conditions, inotropic state, and systemic vascular resistance were eliminated by using the patient as his or her own control. RESULTS: The difference between the measured cardiac output with atrial pacing and ventricular pacing was 1.42 +/- 0.44 L/min in group A in comparison with 0.32 +/- 0.4 L/min in group B (p = 0.001 Wilcoxon signed rank). The percentage of atrial contribution to the cardiac output in group A was 30% +/- 12% (standard deviation), 95% confidence interval in comparison with 7% +/- 9%, 95% confidence interval in group B. The mean stroke volume in group A was higher in sinus rhythm (65 +/- 19.2 ml) and atrial pacing (62 +/- 17.7 ml) compared with ventricular pacing (49.17 +/- 16.43 ml) p = 0.001. In group B no statistical difference was found between stroke volume measured with atrial (47.71 +/- 6.23 ml) or ventricular pacing (46.9 +/- 6.35 ml). CONCLUSIONS: We conclude that the bicaval technique of orthotopic heart transplantation preserve the atrial kick and its contribution to cardiac output early after transplantation.

Atrial Function↗
PubMed1996

TNF alpha mRNA and protein in cardiac transplant biopsies: comparison with serum TNF alpha levels.

OBJECTIVES: To examine the role of TNF alpha (TNF alpha) in cardiac transplant rejection by simultaneous analysis of protein expression and its messenger RNA within serum and grafted tissue. METHODS: 54 endomyocardial biopsy specimens were taken from 19 patients at various times after transplantation. TNF alpha messenger RNA was localised using a digoxygenin labelled complementary DNA probe. An anti-TNF alpha antibody was used to immunohistochemically label the protein product. Serum TNF alpha levels at the time of biopsy were analysed using a specific enzyme-linked immunosorbent assay. RESULTS: TNF alpha mRNA was present in 22/34 endomyocardial biopsies. Eight also contained TNF alpha protein. None had protein alone. Expression did not relate to the grade of rejection in the present or subsequent biopsies. Serum TNF alpha was undetectable (assay sensitivity 30-330 pg/ml) for the majority of specimens. In the nine cases with elevated serum levels, eight samples were from cases within the first 30 days post transplant (r = -0.379; P < 0.05). CONCLUSIONS: Neither tissue TNF alpha mRNA, tissue protein, nor serum TNF alpha relate to the grade of rejection. Furthermore, TNF alpha expression within endomyocardial biopsies is not reflected in the serum. These findings argue against the use of serum analysis as an indicator of cytokine profiles within cardiac tissue allografts. The demonstration of a trend in the early expression of TNF alpha after transplantation suggests that its release may not be specific to the process of rejection.

Adult↗
PubMed1995

Structure-activity study of tripeptide thrombin inhibitors using alpha-alkyl amino acids and other conformationally constrained amino acid substitutions.

In our continuing effort to design novel thrombin inhibitors, a series of conformationally constrained amino acids (e.g. alpha-alkyl, N-alkyl cyclic, etc.) were utilized in a systematic structure-activity study of the P3, P2, and P1 positions of tripeptide arginal thrombin inhibitors. Early examples of this effort include: D-MePhe-Pro-Arg-H (15), Boc-D-Phg-Pro-Arg-H (18), D-1-Tiq-Pro-Arg-H (23, D-1-Tiq = D-1,2,3,4-tetrahydroisoquinolin-1-ylcarbonyl), and Boc-D-Phe-Pro-Arg-H (25).10a,20 The current work clarifies the contribution of each residue of the tripeptide arginals toward the potent and selective inhibition of thrombin relative to that of t-PA and plasmin. The alpha-methylarginal modification in the P1 residue resulted in analogs 30 (D-MePhe at P3) and 32 (D-1-Tiq at P3) which had lower potency toward thrombin while exhibiting improved selectivity. Analogs modified at the P2 site were found to be very sensitive to the conformational changes induced by variations in side chain ring size with the flexible pipecolinic acid 31 being 2 orders of magnitude less potent at thrombin inhibition than the conformationally constrained azetidine analog 20. Examination of the P3 binding region indicated that alpha-alkylphenylglycine residues resulted in a tendency to exhibit substantial improvements in selectivity over the nonalkylated residues. Combinations of optimal P3 and P2 changes led to compounds TFA-D-Phg(alpha Et)-Azt-Arg-H (16), TFA-D-Phg(alpha Me)-Azt-Arg-H (17), Ac-D-Phg(alpha Me)-Azt-Arg-H (21), TFA-D-Phg(alpha Me)-Pro-Arg-H (27), 30, and 32, which are clearly more selective for thrombin versus plasmin than the nonconformationally constrained compounds.

Amino Acid Sequence↗
PubMed1995

Orthotopic cardiac transplantation: a comparison of standard and bicaval Wythenshawe techniques.

We describe an alternative technique for orthotopic cardiac transplantation (bicaval Wythenshawe technique), which maintains the right and left atrial anatomy. We compared the new bicaval technique with the conventional (Lower and Shumway) technique of orthotopic cardiac transplantation to identify any beneficial physiologic and clinical outcomes resulting from maintaining the normal anatomy. Seventy-five patients were randomized on an alternate basis to two groups: group A (n = 40) had orthotopic cardiac transplantation with the bicaval technique and group B (n = 35) had conventional orthotopic heart transplantation. All patients were studied with transthoracic echocardiogram, endomyocardial biopsies, and measurement of intracardiac pressures 1, 4, and 12 weeks after transplantation. There were no statistically significant differences in the demographic profile, ischemic time, bypass time, implantation time, transpulmonary gradient, or pulmonary vascular resistance between the two groups. The hemodynamic data were collected in the absence of histologic signs of rejection. In group A right atrial pressure (mean 3.6 mm Hg) was significantly lower (p < 0.03) than in group B (mean 8.8 mm Hg). The right atrial a wave was recorded in 38 patients in group A compared with seven patients in group B (p = 0.041). Atrial tachyarrhythmias occurred in two patients in group A compared with 11 in group B (p < 0.016). Temporary pacing was required in 10 patients in group A and 16 patients in group B (p = 0.034). Four cases of mitral regurgitation (all mild) were detected in group A in comparison with 12 cases (10 mild, 2 severe) in group B (p = 0.008). The mean ejection fraction in the first week after transplantation was 58% in group A and 46% in group B (p = 0.5). In the first 3 months the need for diuretics was less in group A (mean dose 80.8 mg furosemide daily) than in group B (mean dose 134 mg furosemide daily in the first week increasing to 160 mg furosemide daily). Hospital stay was shorter in group A (mean 23 days) than in group B (mean 27 days) (p < 0.015). There were no early deaths as a result of right ventricular failure in group A (n = 0/40) compared with four (n = 4/35; 9%) in group B (p < 0.034). This difference suggests that bicaval orthotopic cardiac implantation is associated with a lower right atrial pressure, a lower likelihood of atrial tachyarrhythmias, less need for pacing, less mitral incompetence, a lower diuretic dose, and a shorter hospital stay.(ABSTRACT TRUNCATED AT 400 WORDS)

Echocardiography↗
PubMed1995

Detection of human cytomegalovirus antigenaemia: a rapid diagnostic technique for predicting cytomegalovirus infection/pneumonitis in lung and heart transplant recipients.

BACKGROUND: New rapid diagnostic techniques offer the opportunity of early diagnosis of human cytomegalovirus (CMV) infection in immunocompromised patients at risk of developing CMV disease. The use of human CMV antigenaemia as a predictor of clinical CMV infection and disease in lung and heart transplant recipients was studied prospectively. METHODS: Twenty three heart and nine lung transplant recipients who survived 40 days were observed by standard CMV surveillance with serological testing, culture, and by sequential testing for CMV antigenaemia. CMV antigenaemia testing is a rapid and quantifiable technique in which a viral lower matrix protein is detected in cytospin preparations of peripheral blood polymorphonuclear leucocytes (PMNLs) by immunofluorescent staining. RESULTS: Eleven patients developed CMV infection and five developed CMV disease (four pneumonitis, one duodenitis). These clinical events occurred at a median of 65 days following transplantation. CMV antigenaemia occurred in 17 patients at a median of 35 days following transplantation. Detection of CMV antigenaemia had a sensitivity of 100%, a specificity of 93.7%, and a positive predictive value of 94.1% for CMV related illness. CMV antigenaemia was positive at a significant interval before the clinical event. High levels of CMV antigenaemia (> 50 CMV antigen positive cells/2 x 10(5) PMNLs) occurred in 11 patients and five of these developed disease. CMV antigenaemia of > 50 CMV antigen positive cells/2 x 10(5) PMNLs had a positive predictive value of 45.5% for disease but a negative predictive value of 100%. Patients with disease had higher levels of antigenaemia than those without disease. CONCLUSIONS: CMV antigenaemia is a rapid diagnostic technique which can identify patients likely to develop CMV disease, potentially allowing early treatment.

Antigens, Viral↗
PubMed1994

Rejection in heart transplantation strongly correlates with HLA-DR antigen mismatch.

It is well established that incompatible HLA antigens presented by donor tissue readily evoke an immune response. Prospective HLA matching policies, widespread in European kidney transplant centers have reduced the level of HLA mismatching and have significantly improved graft survival. The influence of HLA incompatibility in heart transplantation remains controversial, and prospective HLA matching is seldom achieved. We examined the role of HLA antigen mismatching on transplant rejection by analyzing 2569 endomyocardial biopsies (EMB) from 157 consecutive orthotopic heart transplants performed from April 1987 to August 1993 in our own center. Biopsies were graded according to the accepted International Classification, with grade 2 and higher indicating rejection. Among 91 patients who received a 2 HLA-DR mismatch transplant 34% of 1624 biopsies analyzed were graded as > or = 2. This frequency fell to 29% of 797 biopsies for 53 patients with a one-HLA-DR mismatch and to 18% of 148 biopsies for 13 patients in the zero-HLA-DR-mismatch group (P < 0.00005). No significant effect on EMB grade frequencies was observed using the same method of analysis with transplants mismatched at the HLA-A or HLA-B loci apart from analysis of HLA-B matched transplants at 3 months posttransplant (P = 0.02). The close linkage of the HLA-B and HLA-DR loci may account for this observation. The results of this study show that heart transplants matched at the HLA-DR locus have a significantly reduced incidence of EMB grades indicative of rejection requiring augmented immunosuppressive therapy. We propose that prospective HLA-DR matching should be adopted for allocation of donor hearts for more efficient use of this precious and limited resource.

Adolescent↗
PubMed1994

Survival after postinfarction cardiac rupture in severe aortic valve stenosis.

Myocardial rupture is a lethal complication of acute myocardial infarction. The concurrence of myocardial infarction and hypertension is known to predispose to cardiac rupture. Therefore, it is likely that postinfarction cardiac rupture in the presence of severe aortic stenosis will lead to a rapidly fatal outcome due to the associated left ventricular hypertension. We report survival in a patient with postinfarction left ventricular free wall rupture discovered at operation for severe aortic valve stenosis.

Aortic Valve↗