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J O Lusins

Publications and source records attributed to J O Lusins.

At least 19 recordsLinked to original sources
PubMed1998

SPECT and lumbar MRI in back pain with emphasis on changes in end plates in association with disc degeneration.

Over a two-year period, 48 sequential patients were selected because they showed type I or II end plate changes on magnetic resonance imaging (MRI) and/or had positive single-photon emission computerized tomography (SPECT) scan in the area of disc degeneration. They were selected out of a large group of patients who were being evaluated by MRI and SPECT scan for low back pain. In this group of 48 patients, 47 had positive SPECT scans at the disc space, which on MRI indicates degenerative disc disease. Of these, 38 had end plate changes on the MRI, but 10 did not have end plate changes on the MRI even though their SPECT was positive. None of the 48 patients had evidence of other pathology such as fracture, metastatic disease or spondylolysis. The MRI changes were both of type I and type II and thought to represent increased vascularization of the fibrous tissue or fatty replacement of marrow in the area of the end plate. Based on this study, we are proposing that a positive end plate SPECT in degenerative disc disease is related to marrow changes in the region of the end plate of the disc. Also, we are proposing that SPECT may be of value in delineating early end plate changes prior to the MRI showing type I or type II change in the same area.

Adult↗
PubMed1997

A molecular mechanics and database analysis of the structural preorganization and activation of the chromophore-containing hexapeptide fragment in green fluorescent protein.

We propose that heterologous posttranslational chromophore formation in green fluorescent protein (GFP) occurs because the chromophore-forming amino acid residues 65SYG67 are preorganized and activated for imidazolinone ring formation. Based on extensive molecular mechanical conformational searching of the precursor hexapeptide fragment (64FSYGVQ69), we suggest that the presence of low energy conformations characterized by short contacts (approximately 3 A) between the carbonyl carbon of Ser65 and the amide nitrogen of Gly67 accounts for the initial step in posttranslational chromophore formation. Database searches showed that the tight turn required to establish the key short contact is a unique structural motif that is rarely found, except in other FSYG tetrapeptide sequences. Additionally, ab initio calculations demonstrated that an arginine side chain can hydrogen bond to the carbonyl oxygen of Ser65, activating this group for nucleophilic attack by the nearby lone pair of the Gly67 amide nitrogen. We propose that GFP chromophore-formation is initiated by a unique combination of conformational and electronic enhancements, identified by computational methods.

Chemical Phenomena↗
PubMed1994

SPECT evaluation of lumbar spondylolysis and spondylolisthesis.

Fifty patients with back pain and radiologically diagnosed spondylolysis were evaluated by a single-photon emission computed tomography (SPECT bone scanning). These patients were separated into three groups according to the degree of spondylolisthesis accompanying the spondylolysis. The data obtained from the study indicate that in acute spondylolysis, the SPECT scan is positive at the pars interarticularis. As the spondylolysis becomes chronic, the SPECT scan tends to revert toward normal even though healing of the spondylolysis has not occurred. As spondylolisthesis develops and progresses, the SPECT scan again becomes positive. The positivity, however, is more anterior and more diffuse. The authors propose that SPECT scanning in spondylolysis is not a positive or negative process, but rather varies with the time and stability of the spondylolytic spine.

Adolescent↗
PubMed1994

SPECT evaluation of unilateral spondylolysis.

Three patients with unilateral spondylolysis were evaluated with SPECT and Lumbar CT. All three cases had positive scans. However, the SPECT images were unique to each case. Therefore, the interpretation of the SPECT activity was undertaken in terms of the known natural history of both unilateral and bilateral spondylolysis.

Adolescent↗
PubMed1989

Bone SPECT in patients with persistent back pain after lumbar spine surgery.

Twenty-five patients with persistent pain after lumbar spine surgery for pain were evaluated by single photon emission computed tomography (SPECT) bone scanning. The patients were divided into three groups, depending on the type of surgery performed. The data obtained indicates that lumbar spine SPECT is most useful in conditions where there is the greatest likelihood of instability. The study shows that the improved contrast and better three-dimensional patient information gained through lumbar spine SPECT permits more accurate delineation of the level of maximum instability and stress on the vertebra.

Adult↗
PubMed1989

Nonsurgical management of an isolated interhemispheric subdural hematoma sequentially followed by CT.

Using transaxial CT scan, we diagnosed a patient with head injury as having an isolated interhemispheric subdural hematoma, on the basis of the widening of the superior sagittal sinus. The diagnosis was confirmed by coronal views. The patient was managed nonsurgically and gradual reabsorption of the hematoma was documented by CT. During the latter stages of reabsorption, two parallel lines were noted on the transaxial views as the subdural collection became smaller and drew away from the sagittal sinus. We conclude that an unusual widening of the superior sagittal sinus on transaxial CT scan warrants suspecting an interhemispheric subdural hematoma. Because the hematoma may be obscured by the overlying clot, coronal views may also be valuable.

Female↗
PubMed1981

Degenerative disorders of the cerebellum studied by computerized tomography.

A review of our cases as well as of the clinical and radiological literature indicates that, in instances of cerebellar degeneration, certain CT patterns are constant. The most reliable are: 1. Prominence of cerebellar sulci. These are usually not seen normally, except for some of the primary fissures; in atrophy the sulci are easily distinguished. 2. Enlargement of the superior cerebellar cistern and vermian cistern. 3. Enlargement of the cerebellopontine cistern. This cistern, which is also referred to as the cerebellopontine angle cistern and as the lateral recess of the cerebellopontine cisterns, is particularly prominent when the middle cerebellar peduncle is significantly involved. 4. Enlargement of the pre-pontine cistern, which occurs primarily with involvement of the pons. 5. The fourth ventricle may be enlarged, particularly in conditions where the midline cerebellar nuclei are affected. However, the enlargement of the fourth alone does not have to be associated with a pathological process. As previously established with pneumoencephalographic studies, the size of the fourth ventricle can be variable (14). Likewise, enlargement of the cisterna magna is not usually associated with any pathological condition of the cerebellum (15).

Adult↗
PubMed1981

Multiple meningiomas evaluated by computed tomography.

There were 15 cases of multiple meningiomas in a consecutive series of 168 cases of meningioma studied by computed tomography during the last 5 years. This incidence of 8.9% is significantly higher than the 1 to 3% incidence reported previously. A brief clinical survey of the 15 cases and a description of the location of the meningiomas as demonstrated by computed tomography are presented. The possible cause of the higher incidence and various theories of the etiology of multiple meningiomas are explored.

Adult↗
PubMed1980

Biplane computed tomography of intracranial meningiomas with extracranial extension.

Fifteen of 130 intracranial meningiomas evaluated by biplane computed tomography (CT)--axial transverse and coronal--were found to have direct extracranial extension. These include five pterional meningiomas en plaque with extension to the orbit and temporal fossa; three subfrontal meningiomas invading the paranasal sinuses, nasal cavity, or orbit; three posterior fossa meningiomas with extracranial extension to the neck; three hyperostosing parasagittal meningiomas with extracranial tumors; and one tuberculum sellae meningioma with spread to the optic sheath. Biplane CT is of value in delineating the precise extent of the tumor, both intracranially and extracranially, as well as in evaluating bony changes such as hyperostosis or destruction.

Ethmoid Sinus↗
PubMed1975

Clinical features of chorea associated with systemic lupus erythematosus.

Neurologic complications of systemic lupus erythematosus (SLE) are common, but chorea is rare. Three cases of chorea associated with SLE are presented as well as a review of 28 cases from the world literature. Chorea may be the first and at times the only sign prior to the establishment of diagnosis of SLE. Under such conditions the establishment of the correct diagnosis is difficult, and the chorea may be attributed to a more common etiology, Also the SLE-related chorea may recur in the same subject during the course of the disease. Finally, the chorea associated with SLE can be brought under control by use of haloperidol (HALDAL).

Adult↗