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Biomedical subjects

I W Brown

Publications and source records attributed to I W Brown.

At least 19 recordsLinked to original sources
PubMed2002

Study of the three-dimensional geometry of the central conducting airways in man using computed tomographic (CT) images.

Clinical research on the deposition of inhaled substances (e.g. inhaled medications, airborne contaminants, fumes) in the lungs necessitates anatomical models of the airways. Current conducting airway models lack three-dimensional (3D) reality as little information is available in the literature on the distribution of the airways in space. This is a limitation to the assessment or predictions of the particle deposition in relation to the subject's anatomy. Detailed information on the full topology and morphology of the airways is thus required to model the airway tree realistically. This paper presents the length, diameter, gravity, coronal and sagittal angles that together describe completely the airways in 3D space. The angle at which the airways branch out from their parent (branching angle) and the rotation angle between successive bifurcation planes are also included. These data are from the study of two sets of airways computed tomography (CT) images. One CT scan was performed on a human tracheobronchial tree cast and the other on a healthy male volunteer. The airways in the first nine generations of the cast and in the first six conducting generations of the volunteer were measured using a computer-based algorithm. The data contribute to the knowledge of the lung anatomy. In particular, the spatial structure of the airways is shown to be strongly defined by the central airways with clear angular lobar patterns. Such patterns tend to disappear with a mean gravity, coronal and sagittal angles of 90 degrees in each generation higher than 13-15. The mean branching angle per generation appears independent of the lobe to which the airways belong. Non-planar geometry at bifurcation is observed with the mean (+/- SD) bifurcation plane rotation angle of 79 +/- 410 (n = 229). This angle appears constant over the generations studied. The data are useful for improving the 3D realism of the conducting airway structure modelling as well as for studying aerosol deposition, flow and biological significance of non-planar airway trees using analytical and computational flow dynamics modelling.

Adult↗
PubMed1996

Toward further reducing wound infections in cardiac operations.

BACKGROUND: Serious wound infections such as mediastinitis still occur at a rate of 0.8% to 2.0%, according to the most recently published cardiac operative series. METHODS: Data from careful surveillance for infection have been collected prospectively during a 4.5-year period on 1,717 patients who underwent cardiac operations performed under direct ultraviolet C radiation. RESULTS: The rate for mediastinitis was 0.23%, and for deep incisional infection without mediastinitis, 0.12%; these rates are significantly lower than those for eight of nine of the most recently published cardiac series. When our infection rates were stratified using the National Nosocomial Infection Surveillance risk index, they were also significantly lower in the most important risk categories than the corresponding stratified rates collected from the participating hospitals of the Centers for Disease Control and Prevention National Nosocomial Infection Surveillance system. CONCLUSIONS: Though we lack the proof that only a large, randomized study might provide, certainly, one possible explanation for our lower wound infection rate was the use of bactericidal ultraviolet C radiation during operation. This is a simple and effective means of minimizing operating room airborne bacteria as one possible source of these infections.

Aged↗
PubMed1995

Ceiling-mounted radiographic equipment for trauma management in the emergency room.

Use of ceiling-mounted radiographic equipment in an emergency room for management of the multiply injured patient is described. The protocol of the Advanced Trauma and Life Support manual is followed and three plain radiographs (lateral cervical spine, anteroposterior views of the chest and pelvis) are obtained by the radiographers, who are members of the trauma team. Abnormalities were diagnosed on 7 per cent of the cervical radiographs, 31 per cent of the chest and 28 per cent of the pelvis in 108 patients during the first year of use. With full integration of the radiographers into the trauma team these three initial films are obtained within 10 min. Subsequent films can be taken of skeletal injuries found clinically or incidentally on the first three plain radiographs. It is recommended that all emergency rooms should have a ceiling-mounted radiographic unit with an automatic daylight processor to provide the best service for patients with major trauma.

Cervical Vertebrae↗
PubMed1994

Will Camp Sealy: surgical innovator, scholar, exceptional teacher, and true Georgian.

Will Camp Sealy, MD, Professor Emeritus of Surgery, Duke University 1984 and Mercer University 1992, was born in Roberta, Georgia, in 1912. A 1936 medical graduate of Emory University, he was in surgical residency training at Duke University from 1936 to 1942. During the next 4 years as an army surgeon in World War II, he was promoted to lieutenant colonel and, in the European theater, made chief of surgery of the 121st General Hospital and later the 128th Evacuation Hospital. After the war, he rejoined the surgical faculty at Duke. In 1950, he became chairman of the division of thoracic and cardiovascular surgery, where in the ensuing years he made a number of important initial observations and significant contributions. Among these were studies on the serious paradoxical hypertension that may follow repair of coarctation of the aorta, and on the combined use of hypothermia and perfusion for open heart surgical procedures. In more recent years, his initiation and landmark studies of the surgical treatment of certain cardiac arrhythmias have gained him worldwide recognition and opened one of the last frontiers of cardiac surgery.

Georgia↗
PubMed1988

Coarctation of aorta: late aneurysm formation with Dacron onlay patch grafting.

Repair of coarctation of the aorta using Dacron onlay patch grafting performed in a 2 1/2-year-old child, with subsequent late formation of a true aneurysm on the side of the graft, is reported. Review of the literature did not reveal other cases of late formation of true aneurysm on the side of the Dacron onlay patch graft.

Aortic Aneurysm↗
PubMed1987

Volar intercalary carpal instability following a seemingly innocent wrist fracture.

A case of volar of intercalary carpal instability following a radial fracture is described and the mechanics of injury examined. Such an injury is rare and the type of radial fracture which produced it unusual. Continued instability of the carpus produces late degenerative changes. In contrast to the many reports of early and persistent pain and functional limitation this patient's wrist settled rapidly.

Aged↗
PubMed1987

'False feet': an alternative to expensive surgical shoes.

A method of 'equalising' unequal sized and shaped feet to allow the use of normal shoes of equal size, and permit the purchase of a 'pair' of shoes is described. This makes available a greater choice of normal styles and colours for patients with deformed and unequal feet. It is contrasted with the provision of custom-made surgical shoes and the purchase of two pairs of unequal size shop shoes. The patients and their parents were pleased with the results and the cost savings were considerable.

Adolescent↗
PubMed1985

Osteolytic changes in the upper femoral shaft following porous-coated hip replacement.

Ten uncemented total hip replacements were performed in 1975 using an implant in which the cobalt-chrome femoral stem was coated to give a porous surface. In all but one case a high-density polyethylene head was used. The radiological changes in the upper femoral shafts were assessed between three and nine years later. Seven showed extensive stress-relieving changes, loss of calcar, stress fractures at the root of the lesser trochanter with subsequent detachment, and osteoporosis followed by avulsion of the greater trochanter. In these seven patients the lower part of the stem appeared to be soundly embedded, although in only one was there evidence of bony incorporation. It is suggested that if the fixation of a fully coated implant of this sort remains sound, gross atrophy of the upper femoral shaft develops after five years. This atrophy, associated with an implant which can be removed only at the expense of further bone destruction, presents substantial problems if revision is needed.

Aged↗
PubMed1975

Experimental and clinical experience with hyperbaric oxygen in the treatment of clostridial myonecrosis.

At Duke University Medical Center, 49 patients with proved clostridial myonecrosis were treated with hyperbaric oxygen (HBO) during the past 10 years. Survival in patients with involvement confined to the extremities was 92.3 percent. Survival in patients with combined involvement of extremity and trunk was 53-3 percent, and with primary trunk involvement half of the patients survived. Survival for the entire series was 73.5 percent. Among the 28 patients receiving at least five HBO treatments, 24 survived. Extensive experimental studies were conducted during this same period including in vitro testing and in vivo experimental infections with C. perfringens. Data from the experimental models of gas gangrene indicate a therapeutic benefit with HBO by significantly decreasing both mortality and morbidity rates. The mechanism of action for this appears to be complex but probably includes a direct bactericidal action, bacteriostasis, inhibition of toxin production, and improvement in tissue oxygenation. In the absence of a controlled study, the therapeutic efficacy of HBO in the treatment of clostridial myonecrosis is not fully proved. Nevertheless HBO treatment can be recommended on the bases of sound experimental evidence and the results of favorable clinical experience. Mitigation of this severe but infrequent illness can best be accomplished through prevention, with strict adherence to the principles of wound care.

Adult↗