Biomedical subjects

C A Donnell

Publications and source records attributed to C A Donnell.

6 recordsLinked to original sources

PubMed2001

Methods for estimation of associations between multiple species parasite infections.

Human populations are often infected with more than one species of parasite, especially in developing countries where overall rates of parasitism are high. Infections with multiple parasite species may not necessarily be independent within an individual as physiological, immunological or ecological factors may result in positive or negative associations between infections with different parasite species. A general framework for estimation of these associations is presented. Data from over 215000 individuals are analysed and the associations between geohelminth (Ascaris lumbricoides, Trichuris trichiura and hookworm) and malaria species are investigated. A method is presented for analysing data from multiple communities and testing whether the associations in different communities are equal. Overall estimates of the associations between species are obtained for each country and continent where data were available. Associations between geohelminth species were, in general, found to be positive whilst both positive and negative associations were found between the different Plasmodium species. There was evidence for significant geographical heterogeneity between the associations. A method for using these parameter estimates to predict the distribution of multiple infections when only marginal prevalence data are available is described and demonstrated.

Adult↗

PubMed1998

Renal inflammatory pseudotumor.

A previously healthy 37-year-old man had evaluation of abdominal pain, which had persisted after abrupt onset with fever and hematuria. Although the fever and hematuria had spontaneously resolved after 1 week, the abdominal pain had worsened over a 4-month period. Predicated upon computed tomography and with a presumed diagnosis of renal cell adenocarcinoma, left radical nephrectomy was done. Histopathologic analysis was negative for malignancy but compatible with inflammatory pseudotumor of the urogenital tract--a pathologic entity that is common in the urinary bladder and prostate gland but is rarely diagnosed in the kidney.

Adult↗

PubMed1991

Intraoperative evaluation of intestinal ischemia: a comparison of methods.

Methods for evaluating intestinal ischemia include standard clinical criteria, Doppler ultrasonography, and intravenous fluorescein injection. Each has disadvantages, and a combination of methods is often used. The purpose of this study was to determine whether surface oximetry could be used to assess perfusion in an animal whose intestinal diameter approximates that of infants. Reversible arterial, venous, and arteriovenous occlusion was studied in rabbit intestines. After 6 to 8 hours of occlusion, intestinal vascularity was evaluated by the four methods listed. Doppler ultrasonography and surface oximetry were found to be unreliable tools for assessing perfusion in this animal model. We conclude that standard clinical criteria and fluorescein remain the standards for intraoperative evaluation of intestinal perfusion.

Animals↗

PubMed1990

Corporectomy for intractable sickle-associated priapism.

Priapism is a complication of sickle cell disease, and for those with severe prolonged attacks, it is serious, often resulting in permanent sexual impairment. Treatment is frustrating, and psychological consequences may be profound. A 20-year-old sickle cell patient with intractable priapism associated with intense pain and penile gigantism underwent multiple but unsuccessful medical and surgical treatment regimens. Finally, corpora cavernosa corporectomy was performed. The pathologic findings of extensive vascular thrombosis and stromal fibrosis underscore the irreversibility of this process and explain the inevitable impotence. Pain and sexual impairment were associated with serious psychological difficulties and suicide attempts. Counseling and close follow-up have improved his outlook considerably. He has been pain-free for 1 year, and future management includes consideration of placement of a penile prosthesis.

Adult↗

PubMed1989

Fibrinogen degradation products in fresh frozen plasma. Possible contribution to immunosuppression.

Recent investigations implicate a variety of specific serum factors as immunosuppressive agents, among them variably sized fragments produced by the degradation of fibrin/fibrinogen. Random samples of fresh frozen plasma were tested for fibrinogen degradation products by a latex agglutination method. Thirty-one per cent of the units tested contained greater than 40 micrograms/ml fibrinogen degradation products, and a total of 86 per cent contained greater than 10 micrograms/ml fibrinogen degradation products. Fresh frozen plasma is often used in the treatment of critically ill trauma and surgery patients, and especially in severely burned patients, who are immunosuppressed by the nature of their injury. Since fibrinogen degradation products have been shown to have both in vitro and in vivo immunosuppressive effects, administration of fresh frozen plasma to these patients should be carefully evaluated in light of its potential ability to worsen their already compromised immune status.

Fibrin Fibrinogen Degradation Products↗

PubMed1987

Thyroid carcinosarcoma.

A thyroid carcinosarcoma composed of follicular carcinoma intermixed with osteosarcoma and chondrosarcoma was studied. Results of immunoperoxidase staining for thyroglobulin were positive in the areas of follicular carcinoma and negative in the sarcomatous component. Likewise, the carcinomatous areas showed thyroid epithelial characteristics by ultrastructure, while the sarcomatous areas showed typical mesenchymal differentiation. This is an extremely rare neoplasm, with only 16 cases reported in the literature. It occurs predominantly in elderly women, is thought to arise through a process of neoplastic metaplasia, and has a uniformly dismal prognosis. Immunoperoxidase and ultrastructural studies, the first reported in such lesions, proved helpful in ascertaining the sarcomatous nature of the anaplastic, mesenchymal component of this unusual and aggressive neoplasm.

Adenocarcinoma↗