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Biomedical subjects

S J Morgan

Publications and source records attributed to S J Morgan.

58 records · Page 4Linked to original sources
PubMedDate not supplied

A new fiber optic probe for cellular visualization.

Thrombus formation within artificial organs has been shown, at least in part, to be caused by retarded or stagnant blood flow. The goal of this work was to develop a magnifying fiber optic probe capable of visualizing particle flow and cellular deposition in a physiologically relevant cellular suspension (blood). The probe has minimal cross sectional area to allow for access to confined areas and to minimize flow disturbance. The probe consists of a germanium oxide fiber optic bundle and a gradient index imaging lens. Fluorescent microspheres of 48 microns, 7 microns, and 3 microns in diameter were imaged after deposition on to a cover slip. The flow (1.44 mm/sec) of 3 microns microspheres suspended in buffer alone and with red cell hematocrits of 10%, 25% and 45% were also visualized. To investigate the potential for this probe to detect ongoing thrombosis, fluorescently labeled human platelets were observed depositing on surfaces from a stagnant platelet rich buffer. These initial data suggest that this probe may offer a technique for the visualization of blood cell adhesion on the interior of artificial organs and the local quantification of flow in such devices.

Artificial Organs↗
PubMedDate not supplied

Attitudes of orthopaedic trauma surgeons regarding current controversies in the management of pelvic and acetabular fractures.

A closed-ended questionnaire was mailed to all 363 active members of the Orthopaedic Trauma Association. It directed, toward practicing pelvic and acetabular surgeons, questions pertaining to practice demographics and preferred methods for detection and prevention of deep venous thrombosis (DVT), nerve injury, and heterotopic ossification (HO). Questionnaires were received from 226 surgeons (62 percent). Of the surgeons who responded, 181 (80 percent) perform pelvic-fracture and acetabular-fracture surgery; only questionnaires from this group were analyzed. Standard statistical methods were used to perform both univariate and multivariate analyses. Preoperative DVT screening was performed by 48 percent of the surgeons; ultrasound was the most commonly used modality (82 percent). Preoperative DVT prophylaxis was administered by 88 percent of those surveyed; the majority (78 percent) used sequential compression devices. Postoperative prophylaxis was used by 99 percent; the most commonly used modality was sequential compression devices. Analysis suggests that fellowship-trained surgeons and surgeons in practice for fewer than twenty years are more likely to use preoperative DVT prophylaxis. HO prophylaxis was administered by 88 percent; the most commonly used modality was indomethacin. Intraoperative nerve monitoring was performed by only 15 percent of the respondents. Most surgeons employed prophylactic measures to prevent DVT and HO. The wide variation in type of prophylaxis and reasons for use suggests that controversy will continue, and a standard of care for these conditions has yet to be defined. Very few surgeons use intraoperative nerve monitoring routinely.

Acetabulum↗
PubMedDate not supplied

Healing of transected equine superficial digital flexor tendons with and without tenorrhaphy.

Healing of transected superficial digital flexor tendons was evaluated mechanically and histologically in eight horses. Tendons sutured with polyglyconate had higher loads at failure than nonsutured tendons at weeks 5 and 9. The tendon stress at failure (force per unit area) was higher in the sutured tendons at week 5 but not at week 9, reflecting the increased size of the scar at week 9. Histologically, scars after tenorrhaphy were consistently more mature than nonsutured tenotomy scars. The mean maturity score for sutured tendons was higher than for nonsutured tendons at weeks 5 and 9. Overall, these data support tenorrhaphy with absorbable suture.

Animals↗