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Biomedical subjects

R D Ray

Publications and source records attributed to R D Ray.

At least 19 recordsLinked to original sources

Integrating behavior and cardiovascular responses: the code.

The next revolution in biology is predicted to be in the integrative domain, and the need to involve physiologists in this kind of research has been recognized. This paper represents an approach to providing some of the tools required for dealing with integrative physiology at the behavioral level. Video tape recordings are made of the activities of a group of five baboons (Papio hamadryas) while simultaneous recordings of arterial blood pressure, heart rate, renal blood flow, and mesenteric or iliac blood flow are telemetered from two of the members of the group. The telemetered cardiovascular information is recorded on the two audio channels of the videotape. Subsequently the videotape is viewed, and a two-dimensional code is used to record the behavior of the two animals with the telemetry equipment. The first dimension of the code categorizes the behavior changes precisely regarding those aspects of behavior that are related to cardiovascular dynamics and does so with an accuracy of 16 ms. The second dimension codes relevant environmental changes. The paper describes the code and presents illustrations of how the code reflects the cardiovascular dynamics associated with the behavioral changes.

Animals

Low (type III) odontoid fracture: a new radiographic sign.

Dens fractures are frequently difficult to identify radiographically, particularly when it is only possible to obtain a lateral radiograph of the upper cervical spine. Further, when a dens fracture is identified in lateral projection, it is often difficult to distinguish the "high" (Type II) from the "low" (Type III) fracture. The authors describe an elongated "ring" density superimposed upon the body of the axis in the lateral cervical radiograph which, when horizontally disrupted, indicates a dens fracture and is a specific radiographic sign of the "low" variety.

Axis, Cervical Vertebra

An approach to mid-facial fractures.

The purpose of this article is to present a concept which facilitates the plain film identification of mid-face fractures. The concept evolves from a logical classification of mid-face fractures based upon the region(s) of involvement (orbit, zygoma, maxilla), the extent of the fractures (unilateral or bilateral) and the characteristic distribution of the fracture lines. Recognition of these fractures depends upon an awareness of the fact that the radiographic signs of mid-face fractures differ in certain respects from those involving other skeletal parts. In addition to skeletal disruption, the radiographic signs of mid-face fractures include soft tissue abnormalities which may be localized or diffuse, and which may be either extrinsic or intrinsic to the facial skeleton, alterations of normal skeletal contour, the "bright white line" of displaced fragments, and the subcutaneous emphysema which may also be localized or diffuse. The application of this concept to the roentgen diagnosis of mid-face fractures will be described and illustrated.

Adult

Experimental use of adhesives in the repair of transverse fractures of the rat and rabbit.

In this preliminary study, the feasibility of fixing fractured bones was explored using the ethyl and isobutyl 2-cyano-acrylates, prepolymerized barnacle cement, and fibrin glue. Adequate cohesive strength cannot be obtained when lipids are present on the surface to be joined by alkyl 2-cyanoacrylates. Oxidized regenerated cellulose gauze soaked in a highly concentrated fibrinogen solution was inserted into the partially hollowed fracture ends to arrest the flow of oozing blood from the medullary canal. Anhydrous ether was used to sponge off any residual lipid from the bone surfaces. The displaced fracture ends were aligned and narrow strips of bone were secured around the fracture line resulting in a barrel stave arrangement. Roentgenograms indicated successful reduction of transverse (midshaft) fractures in eight rat (femur) and seven rabbit (tibia) models. In some cases, casts were used as supplementary fixation. Using the ethyl and isobutyl 2-cyanoacrylates, reduced fractures were maintained in a stable position for up to five and six days, respectively. Further study of the 2-cyanoacrylates is recommended. By using a standardized surgical method for testing the usefulness of future adhesives in vivo, consistent interpretation of results will be facilitated.

Animals

Myelography of spinal block from epidural tumor: a new approach.

Eleven patients with spinal canal block from metastatic epidural tumor, documented with Pantopague myelography, were given an additional injection of up to 5 cc of air. This technique forced contrast material past the block in 10 of 11 cases. It failed in one case in which symptoms had been present for 19 days. Air injection allowed visualization of more cephalad lesions and defined the superior extent of the initial obstructing lesion without the need for a lateral cervical or cisternal puncture. It caused transient discomfort but no neurologic deterioration. This technique is less painful, requires less patient cooperation, expedites localization, and does not require the special skills needed for cervical puncture.

Adult

Application of the ACTA-scanner to visualization of the spine.

The development of a new computer program called VISUAL, designed to be applied to a series of cross-sectional ACTA scans of the body, makes possible the three-dimensional visulaization of spinal structure without the necessity of surgical exploration. With VISUAL, a molded three-dimensional image of the spine can be displayed on a CT scanner monitor from any of several angles, or from several angles successively, with the direction of illumination determined by the operator.

Computers

Correlation of arthroscopy with other diagnostic modalities.

In our experience arthroscopy proved to be the most reliable method of evaluating internal derangement of the knee. Among 96 patients who underwent arthrotomy, the arthroscopic diagnosis was confirmed in 96 per cent. The combined anteromedial, anterolateral, and posteromedial approaches consistently demonstrated all intraarticular disorders. We found the posterolateral approach of little benefit.

Adolescent

Base of the neck extracapsular osteotomy for correction of deformity in slipped capital femoral epiphysis.

This is a report on a University of Illinois Hospital series of cases of extracapsular base of the neck osteotomy for slipped capital femoral epiphyses. The osteotomy was performed on 20 hips in 16 patients, with a 71/2 year average follow-up. The results of this procedure are encouraging and illustrate the advantages of technical simplicity and minimal risk of avascular necrosis. The method does not create any additional deformity. The only disadvantage is that the correction could be limited. The maximum correction of posterior tilt was 55 degrees and the maximum correction of varus deformity was 50 degrees.

Adolescent

In vitro studies of transplantation antigens present on bone cells in the rat.

In vitro studies on isolated bone cells were undertaken to investigate the presence of transplantation (histocompatibility) antigens. Bone cells were cultured with allogeneic lymphocytes and exposed to cytotoxic sera containing antibodies against transplantation antigens, to determine their antigenic profile. Preliminary results suggest that bone cells may not express lymphocyte stimulating antigens in an active form, at least after the isolation procedure performed. On the other hand, bone cells were killed by cytotoxic antibodies in a specific way, providing evidence for the presence of serologically defined (SD) transplantation antigens on the cell surface. Additional studies with absorbed sera suggest "sharing" of histocompatibility antigens between bone cells and lymphocytes. The relevance of the surface antigens of bone cells to clinical fields such as bone allotransplantation, susceptibility to various orthopaedic diseases and skeletal sarcomata is discussed.

Animals

Hip fusion utilizing the cobra head plate.

Sixteen consecutive patients underwent hip fusion with fixation by a cobra head compression plate. In six patients on osteotomy of the innominate bone also was done. Four patients had no osteotomy whatsoever, while in six patients medial displacement of the femur was accomplished by centrally dislocating the femoral head through the acetabulum. This modification made the surgical procedure and postoperative care simpler, and rehabilitation was easily accomplished. All of the hips treated in this series had successful bone fusion. All of the patients were out of bed within the first postoperative week, and ambulation with crutches was begun after the second week.

Adult

Cellular and humoral immune response analysis of bone-allografted rats.

Long-term cellular and humoral immune responses were studied in inbred rats in which bone was allografted. Transplants were made across major histocompatibility barriers. Mixed lymphocyte culture tests and humoral cytotoxicity assays were performed in order to determine degrees of cellular and humoral immunity. Grafts of complete bone and of bone free of marrow elicited both types of immune response and it is proposed that transplantation antigens for both types of reaction exist in the bone tissue itself. A gene-dose effect was found. Allogeneic bone grafts gave a stronger reaction than semiallogeneic grafts, and second-set grafts triggered a hypersensitivity type of humoral immune response. This study suggests that until the host-bone graft immunological relationship is better understood, the graft tissue should be matched to the host for major transplantation antigens to help prevent unexpected failures in massive bone allotransplantation.

Animals