Biomedical subjects

F E Schmidt

Publications and source records attributed to F E Schmidt.

14 recordsLinked to original sources

PubMed2001

Time resolved optical tomography of the human forearm.

A 32-channel time-resolved optical imaging instrument has been developed principally to study functional parameters of the new-born infant brain. As a prelude to studies on infants, the device and image reconstruction methodology have been evaluated on the adult human forearm. Cross-sectional images were generated using time-resolved measurements of transmitted light at two wavelengths. All data were acquired using a fully automated computer-controlled protocol. Images representing the internal scattering and absorbing properties of the arm are presented, as well as images that reveal physiological changes during a simple finger flexion exercise. The results presented in this paper represent the first simultaneous tomographic reconstruction of the internal scattering and absorbing properties of a clinical subject using purely temporal data, with additional co-registered difference images showing repeatable absorption changes at two wavelengths in response to exercise.

Adult↗

PubMed1998

Modifying risk for extracorporeal circulation: trial of four antiinflammatory strategies.

BACKGROUND: Despite recent rediscovery of beating heart cardiac surgical techniques, extracorporeal circulation remains appropriate for most heart operations. To minimize deleterious effects of cardiopulmonary bypass, antiinflammatory strategies have evolved. METHODS: Four state-of-the-art strategies were studied in a prospective, randomized, preoperatively risk stratified, 400-patient study comprising primary (n = 358), reoperative (n = 42), coronary (n = 307), valve (n = 27), ascending aortic (n = 9), and combined operations (n = 23). Groups were as follows: standard, roller pump, membrane oxygenator, methylprednisolone (n = 112); aprotinin, standard plus aprotinin (n = 109); leukocyte depletion, standard plus a leukocyte filtration strategy (n = 112); and heparin-bonded circuitry, centrifugal pumping with surface modification (n = 67). RESULTS: Analysis of variance, linear and logistic regression, and Pearson correlation were applied. Actual mortality (2.3%) was less than half the risk stratification predicted mortality (5.7%). The treatment strategies effectively attenuated markers of the inflammatory response to extracorporeal circulation. Compared with the other groups the heparin-bonded circuit had highly significantly decreased complement activation (p = 0.00001), leukocyte filtration blunted postpump leukocytosis (p = 0.043), and the aprotinin group had less fibrinolysis (p = 0.011). Primary end points, length of stay, and hospital charges, were positively correlated with operation type, age, pump time, body surface area, stroke, pulmonary sequelae, predicted risk for stroke, predicted risk for mortality, and risk strata/treatment group interaction (p = 0.0001). In low-risk patients, leukocyte filtration reduced length of stay by 1 day (p = 0.02) and mean charges by $2,000 to $6,000 (p = 0.05). For high-risk patients, aprotinin reduced mean length of stay up to 10 fewer days (p = 0.02) and mean charges by $6,000 to $48,000 (p = 0.0007). CONCLUSIONS: These pharmacologic and mechanical strategies significantly attenuated the inflammatory response to extracorporeal circulation. This translated variably into improved patient outcomes. The increased cost of treatment was offset for selected strategies through the added value of significantly reduced risk.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1996

Leukocyte depletion of blood cardioplegia attenuates reperfusion injury.

BACKGROUND: Leukocytes are associated with myocardial injury during reperfusion after ischemia. Short periods of leukocyte depletion during reperfusion result in persistent attenuation of postischemic myocardial dysfunction. METHODS: Leukocyte depletion was examined in a canine model of regional myocardial ischemia and reperfusion. The extracorporeal circuit and cardioplegia circuits underwent leukocyte depletion by mechanical filtration. Animals were instrumented for baseline global function before 90-minute occlusion of the left anterior descending coronary artery. Global function during ischemia and at 5, 30, 60, and 90 minutes after a 60-minute cardioplegic arrest using continuous blood cardioplegia was assessed in leukocyte-depleted (n = 9) and control (n = 10) groups. RESULTS: No significant difference between groups was seen for systemic leukocyte counts, global function, or water content. Endothelial function was significantly protected as assessed by response to both calcium ionophore (endothelial-dependent, receptor-independent relaxation: leukocyte-depleted, 72% +/- 19% of endothelin-induced constriction versus control, 46% +/- 14%; p < 0.05) and acetylcholine (endothelial-dependent, receptor-dependent relaxation: leukocyte-depleted, 83% +/- 11% versus control, 44% +/- 15%; p < 0.05). CONCLUSIONS: Leukocyte-mediated endothelial reperfusion injury can be attenuated by leukocyte depletion during reperfusion.

Acetylcholine↗

PubMed1989

Differences in the household composition of elders by age, gender, and area of residence.

Using a new procedure for coding the relationships of elders to other household members, we examined age, gender, and area-of-residence differences in household type and generational composition. The majority of elders live in some form of family household; most prevalent are two-person, married-couple-only households at ages 65-79, one-person households at ages 80-89, and two-generation households at ages 90+. Overall, elders are more likely to live in two- than in three-generation households.

Age Factors↗

PubMed1980

Severe upper limb ischemia.

Severe upper limb ischemia is uncommon, and patterns typical of lower limb ischemia are seldom seen. The conditions of 31 patients with actual or threatened gangrene or severe disability were evaluated from 1969 through 1978. Causes of ischemia included emboli, arteriosclerotic occlusions, trauma, thoracic outlet compression, and small-artery occlusions associated with Raynaud's phenomenon, rheumatoid arthritis, or scleroderma. Five patients had emboli from lesions in peripheral arteries, and two patients had ulnar artery occlusions. Twenty-three patients had operations with no deaths. There was one operative failure. Operative angiograms were used routinely. Patients with emboli from the heart received heparin sodium after operation. Sympathectomy improved the conditions of two patients with Raynaud's phenomenon and of one patient with ulnar artery occlusion. One third of the patients had significant arteriosclerotic lesions in other locations.

Adolescent↗

PubMed1980

Aneurysm of anomalous right subclavian artery.

A 67-year-old man presented with a mediastinal mass and multiple arterial emboli to the right hand caused by an aneurysm of an anomalous right subclavian artery. Operative management was successful. We have reviewed other reported cases of this lesion.

Aged↗

PubMed1980