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Biomedical subjects

C D Cook

Publications and source records attributed to C D Cook.

At least 37 records · Page 2Linked to original sources

Thrombomodulin activity and localization.

An overview on the properties, actions and localization of thrombomodulin (TM) in situations of tissue injury and in selected tumors is presented. The localization and activity of TM after injury to vascular endothelium shows that following balloon catheter denudation of the endothelium of the rabbit aorta, the activity and immunohistochemical staining is markedly reduced. The functional and antigenic levels approach the control levels approximately one week after the initial injury. The results suggest that the neointimal smooth muscle cells express TM. This phenotypic plasticity of the neointimal smooth muscle cells may be important in conferring thrombo-resistance to the lumenal lining cells of vessels after injury. Studies are also reviewed on the use of soluble recombinant TM to prevent thrombosis after ligature of vessels in an experimental model. Further characterization on the immunohistochemical distribution of TM in normal tissues and tumors shows that staining with a monoclonal anti TM antibody can be very useful in separating mesotheliomas from pulmonary adenocarcinomas. These studies may lead to insights concerning the role of TM in tissue-injury-repair and tissue differentiation.

Adenocarcinoma↗

Thrombomodulin expression in malignant pleural mesothelioma and pulmonary adenocarcinoma.

Thrombomodulin (TM) is a glycoprotein of molecular weight 75,000 kd that is normally present in restricted numbers of cells, including endothelial and mesothelial cells. In this study, the authors tested the possibility of using anti-TM to facilitate the diagnosis of mesothelioma. All of the 31 mesotheliomas and the two mesothelioma cell lines (MS-1 and MS-2) tested were stained positively with anti-TM. The specificity of anti-TM staining in mesothelioma cells was further confirmed by in situ hybridization of MS-1 cells with a TM-specific probe. The expression of TM in MS-1 cells was increased markedly when these cells were induced by 12-0-tetradecanyl phorbol 13-acetate (TPA) to differentiate. The expression of TM in mesothelioma cells, however, did not correlate with any particular phase of the cell cycle. In an attempt to differentiate pleural mesothelioma from pulmonary adenocarcinoma, the authors compared the expression of TM, carcinoembryonic antigen (CEA), and Leu M1 in these two types of tumors. Only four of 48 (8%) pulmonary adenocarcinomas were stained positively by antibodies to TM. Therefore, immunohistochemical staining with antibodies to TM yielded 100% sensitivity and 92% specificity for diagnosis of mesothelioma. All of the mesotheliomas stained negatively for CEA and Leu M1, except for one, which showed minimal focal positivity for Leu M1. In contrast, 79% and 60% of adenocarcinomas stained positively for CEA and Leu M1, respectively. These findings suggest that immunocytochemical staining with anti-TM should be added to the battery of tests to increase the diagnostic sensitivity and specificity for differentiating mesothelioma from pulmonary adenocarcinoma.

Adenocarcinoma↗

Perforating eye injuries in KwaZulu.

Data on 100 consecutive perforating eye injuries treated at Edendale Hospital, Pietermaritzburg, were collected in order to evaluate some of the features of this condition seen in KwaZulu, and also to assess the outcome of current management. Fifty-six of the injuries were due to assault and 44 were accidental. Fifty injuries involved the anterior segment only, and 50 involved the posterior segment. Only 6 eyes achieved a final visual acuity of 6/12 or better, and 44 eyes ended up with no light perception. Factors contributing to the poor visual results in this Third-World situation include the severity of the injuries and the inadequacy of surgical management within the constraints imposed by limited facilities and expertise. More care is needed in selecting patients with posterior segment injuries, in whom useful ambulatory vision may be salvageable, for vitrectomy and retinal detachment repair. The criteria for such selection should include the nature of the injury, the visual acuity, the presence or absence of an afferent pupil defect, the extent of the injury found at the time of repair, the presence and extent of vitreous haemorrhage, and the findings on ultrasonography.

Adolescent↗

Thrombomodulin activity on human saphenous vein grafts prepared for coronary artery bypass.

Thrombomodulin, a membrane glycoprotein present on normal vascular endothelium, binds circulating thrombin and is important in protein C activation. These functions contribute to the nonthrombogenic nature of endothelium. Damage during harvest and ex vivo storage of vein grafts may result in dysfunction of this endothelial anticoagulant barrier and possibly contribute to early graft thrombosis. We studied the functional activity and antigenic expression of thrombomodulin on saphenous veins before (initial) and after (harvested) harvest and storage for coronary artery bypass grafting in 15 patients. Also, fresh saphenous vein was studied after mechanical endothelial stripping. After storage for 2.7 +/- 0.6 hours at room temperature in heparinized saline, thrombomodulin functional activity in harvested vein segments was 28% less than initial segments (p = 0.08). Endothelial stripping resulted in a 79% reduction in thrombomodulin activity compared with initial segments (p = 0.04). Immunohistochemical staining confirmed thrombomodulin antigen on vein grafts after harvest and storage, but not on segments stripped of endothelium. Thrombomodulin functional activity and antigenic expression on human saphenous vein grafts is not significantly changed by harvest and relatively short periods of storage at room temperature in heparinized saline.

Antigens↗

Tuberculosis of the conjunctiva occurring in association with a neighbouring lupus vulgaris lesion.

A case of tuberculosis of the conjunctiva in association with a neighbouring lupus vulgaris lesion is reported. Both lesions resolved within one month of starting antituberculous therapy. Tuberculosis of the conjunctiva is nowadays a rare condition. It should be considered in the differential diagnosis of any unusual chronic conjunctivitis, particularly in patients who are at risk of contracting tuberculosis.

Adult↗

Clinical algorithms teach pediatric decisionmaking more effectively than prose.

Despite the rapidly increasing volume of medical literature, little attention has been paid to the appropriate printed format for teaching clinical content. This study attempted to determine whether a clinical algorithm (CA) or prose is more effective for teaching clinical decisionmaking. Clerkship students, preclerkship students, and pediatric house officers in five medical centers in the USA and Israel were presented with clinical algorithms and prose describing management of fever in a child under 2 years of age, and management of meningitis in children. Knowledge of decisionmaking was measured before and after learning, using audio-taped clinical problems and learning time as measured. It was concluded that CAs are more effective and more efficient than prose for teaching clinical decisionmaking. When writing about clinical decisionmaking, the use of CAs should always be considered, especially if a series of interdependent decisions is being described.

Algorithms↗

Moral reasoning and decisions in dilemmas of neonatal care.

The relationship between levels of moral reasoning and decisions in dilemmas of neonatal care was investigated in a sample of 452 pediatricians. Subjects included residents, faculty members, and practitioners recruited from a variety of university-affiliated and community hospitals. It was hypothesized that physicians whose moral reasoning was more fully developed would less actively treat particular cases. Such cases might include those where a patient's family requested such a limit (designated "negative family attitude") or the quality of life likely to be led after therapy was so low as to preclude even a minimal degree of human activity or social interaction (designated "unsalvageable prognosis"). The hypothesis was tested through the use of two questionnaires. The first questionnaire, devised by Crane, assessed the physician's reported degree of activism in treating six cases of infants born with severe defects. The structure of moral reasoning was measured by a second questionnaire, Rest's Defining Issue Test. Subjects were scored by the degree to which they use universal, ethical principles in resolving a series of moral dilemmas. Results of the absolute level of activism (Table 1) showed that among both residents and postresidents, the degree to which cases are actively treated depends, for salvageable patients, on the type of damage and on the possibility for research. Results involving moral reasoning showed a different pattern among residents and postresidents. Among residents, a significant correlation exists between principled reasoning and the absence of active treatment (r = - 0.41, Form A; r = - 0.23, Form B). As predicted, such correlations were strongest for cases of negative family attitude or of unsalvageable prognosis. The pattern of correlations among postresidents showed either no relationship to moral reasoning or the reverse of the residency pattern (r = -0.08, Form A; r = 0.30, Form B). The influence of the type of institution a resident operates within was assessed by analysis of variance. Inasmuch as moral reasoning and institutional type both had significant main effects (Form A), their magnitude differed. Institutional type accounted for 43% of the variation in mean activism scores whereas moral reasoning accounted for only 4%; however, because one could, a priori, expect institutional norms and customs to be powerful determinants of behavior, any additional, identifiable influence deserves attention. The structure of individuals' moral reasoning seems to be such an influence.

Attitude of Health Personnel↗

A review of pediatric inpatient care.

Between 101 and 188 medical records of children hospitalized in each of three community hospitals and one major teaching hospital were examined to determine need for admission and quality of care administered. Two of the hospitals had been similarily studied two years before. Twenty-five percent of all admissions and 17% of all patient days were considered unnecessary. The smallest number of inappropriate admissions was found in the major teaching institution, but one of the community hospitals without any teaching affiliation was notably better than the other two. The teaching hospital and the same community hospital also achieved the lowest questionable management rates. Significant (P less than 0.5) but minimal reduction had occurred in number of unnecessary admissions when first and second utilization studies in these two hospitals were compared.

Child↗