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Biomedical subjects

W B Forman

Publications and source records attributed to W B Forman.

47 records · Page 3Linked to original sources
PubMed1976

Fibrin formation: the role of the fibrinogen-fibrin monomer complex.

The process of fibrin formation using highly purified fibrinogen and thrombin was studied using laser fluctuation spectroscopy, a method that rapidly determines particle size in a solution. Two periods in fibrin clot formation were noted: an induction period during which no fibrin polymerization occurred and a period of rapid increase in particle size. Direct measurement of fibrin monomer polymerization and fibrinopeptide release showed no evidence of an induction period. These observations were best explained by a kinetic model for fibrin clot formation incorporating a reversible fibrinogen-fibrin monomer complex. In this model, the complex serves as a buffer system during the earliest phase of fibrin formation. This prevents the accumulation of free polymerizable fibrin monomer until an appreciable amount of fibrinogen has reacted with thrombin, at which point the fibrin monomer level rises rapidly and polymerization proceeds. Clinically, the complex may be a homeostatic mechanism preventing pathological clotting during periods of elevated fibrinogen.

Animals↗
PubMed1976

Criteria for the differentiation of dysfibrinogenemic states.

A large number of families have now been described in whom affected individuals have within their plasmas an abnormal species of fibrinogen (factor I). These defects, presumably examples of the phenomenon of allotypy--i.e., the synthesis of variant forms of a normal protein--have been inherited as autosomal dominant characteristics. In the great majority of cases, clotting is abnormally slow when thrombin is added to the abnormal plasma. Sometimes this defect appears to reside in impaired release of fibrinopeptides by thrombin. In other cases, fibrinopeptide release proceeds normally, but aggregation of fibrin monomers is impeded. In the latter instance, aggregation may be abnormally slow or, once it begins, it may proceed at a normal rate. Curiously, a bleeding tendency is more likely to occur in patients in whom fibrinopeptide release is impaired, while dehiscence of operative wounds rarely complicates dysfibrinogenemias associated with impaired aggregation of fibrin monomers; thrombosis has been described in both groups of patients. Most of the reported cases may be distinguished by functional criteria and by the physicochemical behavior and biochemical nature of the abnormal protein. Additonally, one family has been described in which plasma clots abnormally rapidly upon addition of thrombin, and two others in which crosslinking of fibrin by fibrin-stabilizing factor (factor XIII) is defective.

Afibrinogenemia↗
PubMed1973

Studies on the nature of antihemophilic factor (factor VIII). Further evidence relating the AHF-like antigens in normal and hemophilic plasmas.

Normal human antihemophilic factor (AHF, factor VIII) and the protein antigenically related to it in hemophilic plasma both appeared in the void volume of columns of agarose (Sepharose 4B) during purification of these agents. On ultracentrifugation upon sucrose gradients, both agents had sedimentation characteristics similar to those of an S30 marker. After reduction, the polypeptide chains of purified normal AHF and of the nonfunctional agent from hemophilic patients had an apparent molecular weight of 200,000 as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. These observations suggest that AHF, purified as described, exists as a large molecule with subunits of molecular weight of approximately 200,000. Antisera to normal AHF and the nonfunctional agent from hemophilic plasma appeared to be directed against antigens of similar electrophoretic mobility and precipitating characteristics, present in normal and hemophilic plasma but deficient in severe von Willebrand's disease plasma. Both antisera neutralized the AHF clot-promoting activity present in normal plasma, and this property was removed by absorption of the antisera with concentrates of normal or hemophilic plasma but to a greatly reduced extent by concentrates of von Willebrand's disease plasma. These findings suggest that the antigen detected in normal plasma by the antisera appears on a molecule participating in the AHF clot-promoting reaction.

Animals↗
PubMedDate not supplied

On the 10th anniversary of the organization of the American Academy of Hospice and Palliative Medicine (AAHPM): the first 10 years.

The American Academy of Hospice and Palliative Medicine (originally chartered as the Academy of Hospice Physicians in 1988) is an organization of physicians devoted to advancing hospice and palliative medicine in the United States. The academy's mission is "physicians dedicated to promoting quality hospice care for the terminally ill through medical education, research, and training." The academy obtained specialty recognition from the AMA in 1996 and became the first physicians' group to publish its position on physician-assisted suicide in 1991 and again in 1997.

Forecasting↗
PubMedDate not supplied

Formal geriatric assessment, An imperative for the older person with cancer.

PURPOSE: The authors evaluate the role of cognitive, functional, and affective geriatric assessment measures in elderly cancer patients, and analyze the associations between these factors, stage of malignancy, and cancer treatment choices. DESCRIPTION: Fifty consecutive patients older than 65 years of age who were referred to the Geriatric Oncology Clinic at the University of New Mexico Health Sciences Center in Albuquerque were evaluated using standard geriatric assessment tools. Each person underwent a complete history and physical examination. An extensive chart review established the type of cancer, stage at diagnosis, and treatment modalities used. The Karnofsky performance status scale score also was determined at this initial evaluation. RESULTS: The group had a mean age of 74.9 years; 60% were women and 40% were men. The most common cancers were breast (28%) and prostate (16%). Fifty-two percent of the patients had localized disease and 48% had distant disease. Seventy-four percent had received treatment by the time of the initial assessment, with 62% undergoing combination therapy. The most common noncancer diagnoses were cardiovascular disease, hypertension, and osteoarthritis. Scores on standardized measures indicated that the majority of patients were independent. Those who did not receive treatment were more functionally impaired than those who received treatment. Twenty-seven percent of the sample were impaired cognitively and 24% were depressed. There were no statistical differences in functional, cognitive, or affective status between stages of disease for specific malignancies. CLINICAL IMPLICATIONS: Age alone is a poor predictor of outcome in cancer treatment and is an inappropriate factor by which to exclude persons with cancer from clinical trials. Treatment decisions based on age alone may lead to inadequate treatment. In this report, functional dependence was more prevalent in nontreated patients and was unrelated to the stage of disease. These results support the need for formal geriatric assessment, including measures of cognitive, functional, and affective status, in elderly persons with cancer. Further studies on the role of functional, cognitive, and affective status at the time of cancer diagnosis, as well as how these parameters might alter treatment decisions, are warranted. In addition, further investigation to identify which of these multiple variables influence treatment outcome are needed.

Activities of Daily Living↗