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Biomedical subjects

N E Chase

Publications and source records attributed to N E Chase.

At least 19 recordsLinked to original sources
PubMed1990

Two distinct lymphocyte populations mediate simian immunodeficiency virus envelope-specific target cell lysis.

The relative contributions of the effector lymphocyte responses to the AIDS virus envelope glycoprotein (env) were explored in simian immunodeficiency virus of macaques (SIVmac)-infected rhesus monkeys. CD8+, MHC class I-restricted, env-specific CTL were cloned from PBL of SIVmac-infected monkeys, indicating that such cells constitute a component of the env-specific effector lymphocyte response. A limiting dilution 51Cr release assay was then established for quantitating the frequency of SIVmac-specific effector lymphocytes in PBL of rhesus monkeys. Using this assay we demonstrate that SIVmac env-specific effector lymphocytes are comprised of both CD16-, MHC class I-restricted and CD16+, MHC class I-unrestricted cells. We also demonstrate that the env-specific response is the predominant SIVmac-specific effector lymphocyte response in rhesus monkeys. These studies document the complexity of the effector lymphocyte response to the AIDS virus envelope glycoprotein and establish the role played by two distinct effector cell populations in this response.

Animals↗
PubMed1989

Volumetric rendering of MR images.

The authors developed new techniques for three-dimensional display of magnetic resonance (MR) images that preserve soft-tissue definition, are fully automatic, and work with routinely used section thicknesses. MR images are segmented, selectively enhanced, and displayed by means of a volumetric rendering algorithm. These techniques were used to illustrate normal anatomy of the brain, knee, and liver. Three-dimensional rendering of balanced spin-echo images shows the ventricles and extracerebral veins and of T1-weighted images, the sulci and gyri. The large hepatic and portal vessels can be seen with these enhancement techniques. Three-dimensional views of the knee reveal articular surfaces of the tibia and clearly depict menisci and posterior and anterior cruciate ligaments. These techniques make it possible to image multiple soft tissues simultaneously while preserving the detail contained in the original images. Three-dimensional presentation of complex, overlapping anatomic regions is helpful in surgical planning and should lead to improved diagnosis.

Algorithms↗
PubMed1983

Computed tomography of spinal tuberculosis.

The computed tomographic (CT) features of nine documented cases of spinal tuberculosis are analyzed. The mechanisms of vertebral involvement are reviewed. The ability of CT to facilitate the diagnosis as well as to delineate the extent of soft tissue involvement is emphasized. The need for increased alertness to the diagnosis of tuberculosis is stressed.

Adult↗
PubMed1981

Stereotactic surgical system controlled by computed tomography.

The three-dimensional data obtained by computed tomographic (CT) scanning offer an advantage in using this imaging technique for stereotactic surgical procedures. This requires interfacing of CT image data with a stereotactic guide. In the performance of functional procedures where the surgical target must be identified from brain landmarks, such as the anterior and posterior commissures, an image reconstruction technique that presents in an image high spatial resolution structural information must be used. The description of a fully hardware- and software-interfaced CT-directed stereotactic surgical system is presented. The logic of operation and examples of images reconstructed with a high spatial resolution algorithm are illustrated. The experimentally determined measurement of an electrode tip localization with this system is within 1 pixel or +/- 0.5 mm in any direction.

General Surgery↗
PubMed1977

Dense intracranial epidermoid tumors. Computed tomographic observations.

Three extra-axial posterior fossa epidermoid tumors manifested nearly identical CT appearance of large size, sharp margination, apparently homogeneously increased attenuation in the range of 80-120 Hounsfield units, and absence of contrast-agent enhancement. This constellation of findings is distinctly different from that reported previously, and appears to be characteristic for some epidermoid tumors.

Adolescent↗
PubMed1976

Evaluation of sellar and parasellar masses by computed tomography.

Computed tomography is the method of choice for initial evaluation of patients with potential suprasellar masses. In our experience, CT has proved completely reliable for detecting or ruling out the presence of a suprasellar mass, the direction and degree of parasellar extension, and the presence of any calcific or cystic component of the lesion. When multiple cut CT has been negative, further diagnostic studies have proved unrewarding. When CT has been positive, additional studies have been required in some cases to rule out aneurysm prior to craniotomy.

Adenoma↗
PubMed1976

Computed tomography in the diagnosis of extra-axial posterior fossa masses.

Extra-axial posterior fossa masses can be diagnosed reliably by computed tomography (CT) in most cases. Acoustic and trigeminal neurinomas, meningiomas, cholesteatomas, and other extra-axial masses can usually be distinguished from intra-axial masses by asymmetric widening of the basal subarachnoid spaces, bone destruction, continuity of the tumor mass with the tentorium or bone, and more sharply defined margins. Multiple-cut study of the posterior fossa improved visualization of the fourth ventricle and basal cisterns. Interpretation of cisternal changes in association with changes in the fourth ventricle and abnormal attenuation coefficients permits accurate diagnosis of posterior fossa masses.

Aneurysm↗
PubMed1976

Role of computerized axial tomography in diagnosis and treatment of common neurosurgical problems of infancy and childhood.

Computerized axial tomography (CAT) is a new, highly accurate technique for studying the skull and intracranial contents. It is rapid enough to be utilized in acute emergencies and safe enough to be utilized for routine serial followups and evaluation of outpatients with equivocal findings. Because CAT can delineate the ventricular system without need for contrast agent, can distinguish clearly between hematoma and edema and can differentiate cystic from solid tumors, it finds wide application in the evaluation of neurological disease.

Brain Diseases↗