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Biomedical subjects

J S Ross

Publications and source records attributed to J S Ross.

At least 19 recordsLinked to original sources
PubMed1992

Magnetic resonance imaging lesion enlargement in multiple sclerosis. Disease-related activity, chance occurrence, or measurement artifact?

Magnetic resonance imaging (MRI) may demonstrate disease activity in a number of ways in patients with multiple sclerosis. Newly appearing MRI lesions, gadolinium-enhancing lesions, and enlargement of preexisting lesions are frequently taken as evidence of disease activity. Furthermore, serial MRI studies have been stated to be more sensitive than repeated neurologic examinations in detecting disease activity. We assessed the validity of using lesion enlargement as a measure of disease activity by repeatedly measuring the area of all MRI lesions in four patients with multiple sclerosis. The size-frequency distribution in all patients was similar, with 80% of the lesions measuring less than 0.67 cm2. The median coefficient of variation for three successive lesion measurements was inversely related to lesion area, ranging from 22.6% for the more common smaller lesions (less than 0.67 cm2) to 12.1% for larger lesions. Based on these coefficients of variation, a change in a particular lesion exceeding 45.2% for a baseline lesion smaller than 0.67 cm2 and 24.2% for a baseline lesion greater than or equal to 0.67 cm2 should be required to exclude a change due to measurement variability. It remains necessary to determine the number of lesions that must change when multiple lesions are present in the baseline MRI to reliably exclude chance occurrence when establishing MRI-evident disease activity. Guidelines for determining these criteria are presented, as are the limitations inherent in the statistical model employed to make these determinations.

Humans↗
PubMed1992

Primary hepatic leiomyosarcoma in a child with the acquired immunodeficiency syndrome.

We report the first case of acquired immunodeficiency syndrome (AIDS)-related primary hepatic leiomyosarcoma in a 9-year-old girl. The pathologic diagnosis was made on a partial hepatectomy specimen and was confirmed by immunohistochemistry and electron microscopy. No human immunodeficiency virus-related nucleic acid was identified in tumor cells by in situ hybridization. Review of the AIDS-related literature reveals a rising incidence of tumors of smooth muscle origin in human immunodeficiency virus-infected patients. This case study details the eighth pediatric AIDS patient with a tumor of smooth muscle origin and represents the 20th and the youngest patient with primary hepatic leiomyosarcoma to be reported in the world literature.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Correlation of tumor cytosol cathepsin D with differentiation and invasiveness of endometrial adenocarcinoma.

The lysosomal acidic protease cathepsin D, a recognized independent predictor of prognosis in human breast cancer, has not been studied widely in patients with endometrial adenocarcinoma. Cathepsin D levels (52-kD precursor plus 48-kD intermediate and 34/14-kD mature form) were measured in tumor cytosols from 26 hysterectomy specimens by immunoradiometric assay. Significant correlation between cathepsin D levels and tumor differentiation was noted with linear increase in cathepsin D from 8 pmol/mg (standard error of the mean [SEM], 1.73 pmol/mg) for Grade I tumors to 28 pmol/mg (SEM, 3.91 pmol/mg) for Grade III tumors. A group of four papillary serous carcinomas showed relatively high cathepsin D levels reaching 39 pmol/mg. A significant stepwise increase in cathepsin D levels was associated with increased depth of myometrial invasion. Noninvasive tumors averaged 7 pmol/mg (SEM, 4.0 pmol/mg); intramural tumors averaged 15 pmol/mg (SEM, 2.45 pmol/mg); and transmural invasive tumors averaged 30 pmol/mg (SEM, 3.72 pmol/mg). There was no significant correlation of cathepsin D levels with age, estrogen/progesterone receptor hormone status, clinical stage, and lymph node metastasis. Cathepsin D levels correlate significantly with tumor differentiation and myometrial invasiveness and may show promise as a clinically useful adjunct to prognosis assessment and the planning of therapy for patients with endometrial adenocarcinoma.

Adenocarcinoma↗
PubMed1992

Intracranial magnetic resonance imaging.

Magnetic resonance angiography (MRA) is currently being incorporated into the routine MR evaluations of patients with suspected cerebrovascular disease. Currently, MRA serves as a useful adjunct to routine parenchymal spin-echo imaging of the head. Intracranial MRA is predominantly used as a screening test for cerebrovascular disease in situations where the clinical suspicion and/or the patient's physical condition does not warrant a conventional arteriogram. Clinical experience to date suggests that MRA can play a significant role in the evaluation of patients with suspected intracranial aneurysms, arteriovenous fistulae, large vessel occlusive disease, and dural sinus occlusion/thrombosis. MRA has not yet reached the point where it can replace conventional catheter angiography. This is most apparent when trying to evaluate 1) larger vessels which are typically difficult to visualize due to higher order motion terms (eg, carotid siphon); 2) the smaller cortical branches with relatively slow flow that would be necessary to see in patients with suspected vasculitis; and 3) any situation in which dynamic information is important such as with mass lesions or vascular malformations. These limitations must be taken into account when deciding on the appropriate imaging study for an individual patient. Large-scale, well-controlled prospective clinical trials will ultimately determine the role intracranial MRA will play in the evaluation of patients with suspected cerebrovascular disease.

Brain↗
PubMed1992

Effect of in vivo interleukin-1 on adhesion molecule expression in normal human skin.

We have examined the expression of three endothelial adhesion molecules (intercellular adhesion molecule-1 [ICAM-1], endothelial leukocyte adhesion molecule-1 [ELAM-1], and vascular cell adhesion molecule-1 [VCAM-1]) in normal human skin following intradermal injection of stratum corneum-derived interleukin-1 alpha (SCIL-1 alpha). In control skin, constitutive expression of ICAM-1 was found on endothelial cells and at low levels on dermal dendritic cells but not on keratinocytes. ELAM-1 and VCAM-1 were present in low levels on endothelium and perivascular dendritic cells, respectively. SCIL-1 alpha injection produced marked endothelial ELAM-1 upregulation. Double staining with neutrophil elastase demonstrated that many ELAM-1-positive vessels contained marginating neutrophils and that interstitial neutrophils were clustered around ELAM-1-positive vessels. An increase in dermal dendritic cell ICAM-1 expression occurred and in two of three biopsies there was keratinocyte expression of ICAM-1 in the SCIL-1 alpha-injected tissue. Also, there was upregulation of VCAM-1 on vascular endothelium and an increase in the dermal dendritic cell expression of this molecule. These results give in vivo confirmation that SCIL-1 alpha modulated endothelial and dermal dendritic cell adhesion molecule expression, and show that endothelial VCAM-1 is regulated in vivo by SCIL-1 alpha, thus providing a regulatable ICAM-1-independent means of mononuclear cell recruitment.

Adult↗
PubMed1992

Recalcitrant pyoderma gangrenosum--two cases successfully treated with cyclosporin A.

The successful use of cyclosporin A (CSA) in organ transplantation is now well established. In recent years its usefulness has extended to the treatment of cutaneous autoimmune disorders, including pyoderma gangrenosum (P.G.). We report two further cases of recalcitrant P.G., both associated with rheumatoid arthritis (R.A.) which responded to low dose CSA.

Aged↗
PubMed1992

Unusual variants of pemphigoid: from pruritus to pemphigoid nodularis.

We report three patients with pemphigoid nodularis. Patients were females aged 76, 71 and 50 years, and all had features of bullous pemphigoid together with prurigo-like lesions at some stage of their illness. In two cases, nodular lesions preceded the onset of blistering by some months. Blisters arose on normal skin and in one patients also at sites of prurigo lesions. Routine histology of bullous lesions revealed the presence of subepidermal blisters. Electron microscopy performed in two cases confirmed the level of split to be through the lamina lucida. Direct immunofluorescence in all cases was positive, with linear basement membrane zone deposition of IgG and C3. Circulating IgG anti-basement membrane antibody was also detected in all patients, and in two, immunoblotting revealed a single antigen of 220 kD.

Aged↗
PubMed1992

MR imaging of the cervical spine: techniques for two- and three-dimensional imaging.

This review briefly describes two-dimensional (2D) and three-dimensional (3D) MR imaging of the cervical spine and focuses on the current and potential clinical usefulness of 3D sequences in the evaluation of cervical spine abnormalities. The practical advantages of 3D imaging are several, and include an increase in signal-to-noise ratio over 2D imaging, thin contiguous slices, more accurate slice thickness, and optimal computer postprocessing. Different 3D techniques can provide either high- or low-signal-intensity CSF, with excellent suppression of CSF pulsation artifacts.

Artifacts↗
PubMed1992

Magnetic resonance imaging of adult intra-axial brain tumors.

The detection and characterization of intra-axial tumors in the adult have been greatly improved with the advent of magnetic resonance (MR) imaging, particularly when combined with paramagnetic contrast enhancement. MR imaging allows tumor localization along with evaluation of edema, tumor margins, intrinsic signal intensity on T1- and T2-weighted sequences, and the presence or absence of enhancement. Consideration of these characteristics together with pertinent clinical history forms the basis of a reasonable differential diagnosis. The article summarizes the MR imaging characteristics and pathologic findings of the major intra-axial tumors of adults with emphasis on differential considerations.

Adult↗
PubMed1992

Helicobacter pylori. Its role in the pathogenesis of peptic ulcer disease in a new animal model.

The association and causative role of Helicobacter pylori infection of the stomach with gastric ulcer, duodenal ulcer, non-ulcer dyspepsia, and gastritis has remained controversial. The authors studied the effects of daily intragastric administration of H. pylori suspension in saline (10(8) CFU/ml) and bacteria-free filtrates of saline H. pylori suspensions in 85 Sprague-Dawley rats (weight, 150 to 200 g) with normal mucosa and with surgically produced experimental gastric ulcers. Group I rats (n = 30) with pre-existent experimental gastric ulcers received H. pylori suspension (ATCC 43504, 10(8) CFU/ml); Group II rats (n = 20) with experimental gastric ulcers received bacteria-free H. pylori filtrates; Group III rats with ulcers (n = 20) received saline alone; and Group IV control rats (n = 15) without ulcers received intact H. pylori organisms in suspension (ATCC 43504, 10(8) CFU/ml). At death, ulcer surface areas were measured with a dissecting microscope. Full-thickness sections were obtained for quantitative and qualitative histologic parameters, including the area of remaining mucosal necrosis; characteristics and cellular composition of restored mucosal architectures; and presence or absence of inflammation including counts of neutrophils and lymphocytes. H. pylori organisms were identified within the surface mucus and crypts using routine, special, and immunohistochemical stains. Our results indicate that the continued presence of either intact H. pylori organisms or bacteria-free H. pylori filtrates in the stomachs of rats with pre-existent gastric ulcers resulted in delayed healing of the ulcers and persistence of chronic active inflammation. Daily administration of suspensions of H. pylori organisms to sham-operated rats with intact gastric mucosa, however, resulted in no ulceration or inflammation despite identification of surface H. pylori organisms at death. The authors conclude that H. pylori alone causes little or no effect on an intact gastric mucosa in the rat, that either intact organisms or bacteria-free filtrates cause similar prolongation and delayed healing of pre-existing ulcers with active chronic inflammation, and that the presence of predisposing factors leading to disruption of gastric mucosal integrity may be required for the H. pylori enhancement of inflammation and tissue damage in the stomach.

Animals↗
PubMed1992

Current assessment of spinal degenerative disease with magnetic resonance imaging.

Radiography (plain roentgenography, myelography, computed tomography (CT), computed tomographic myelography) has been used to identify morphologic changes involving the various components of the diskovertebral unit. Added to this armamentarium of imaging techniques is magnetic resonance (MR) imaging, with its superior ability to define anatomy, its improved contrast sensitivity, and its potential to provide unique biochemical and physiologic information. The authors review the current use of MR imaging in defining degenerative changes in the spine including the various patterns of herniation, annular tears, canal stenosis, and the use of gadolinium-diethylenetriamine-pentaacetic acid for previously unoperated and operated patients. Prospective studies have compared surface-coil MR imaging, CT, and myelography in the evaluation of disk herniation and stenosis and found an 82.6% accuracy between MR imaging and surgical findings for the type and location of the disease. Recent experience with precontrast and postcontrast MR imaging in the postoperative lumbar spine indicated that it was 96% accurate in differentiating scar from disk in 44 patients at 50 reoperated levels. Three-dimensional imaging is, more and more, becoming an integral part of routine MR imaging. The theoretical and practical advantages of three-dimensional imaging are several and include a theoretical increase in the signal-to-noise ratio over two-dimensional imaging (by the square root of the number of partitions selected), the ability to obtain thin contiguous slices from the volume without the problem of cross-talk found in two-dimensional imaging, more accurate slice thickness than that achieved in two-dimensional imaging, and a reduction in susceptibility artifacts. Different three-dimensional techniques are capable of providing either high or low signal intensity cerebrospinal fluid (CSF), with excellent suppression of CSF pulsation artifacts. Certain sequences provide a high enough signal intensity that a computer algorithm may be used to display the CSF in a rotating three-dimensional manner, similar to a myelogram. This three-dimensional myelographic image has the potential of providing the clinician with a global assessment of the CSF spaces, an advantage previously lacking with other imaging techniques.

Contrast Media↗
PubMed1992

Diagnosis of nerve root compression. Myelography, computed tomography, and MRI.

Current technology and published studies support the preferential use of MRI in the diagnosis of cervical myelopathy. In cervical radiculopathy, data support the use of either contrast-enhanced CT or MRI. We prefer MRI as the initial diagnostic test because of the obvious advantage of its noninvasive nature. Similar to myelography, MRI permits visualization of the entire cervical canal and spinal cord. Unlike routine CT, MRI visualizes the spinal cord and nerve roots in two planes and is better in detecting unsuspected pathology at other cervical segmental levels. Because the quality of MRI scans in the cervical spine is subject to more variation than in the lumbar spine, anticipated pathology is sometimes not clearly visualized by cervical MRI. Under such circumstances, we obtain a water-soluble myelogram followed by contrast-enhanced CT. Because inaccurate radiographic diagnosis is one of the identifiable causes of poor outcome in surgical therapy for cervical spondylosis, accurate visualization of pathology in terms of its location, nature, and extent is imperative before performing decompressive cervical spine surgery.

Contrast Media↗
PubMed1992

DNA ploidy of oncocytic-granular renal cell carcinomas and renal oncocytomas by image analysis.

DNA ploidy analysis of five renal oncocytomas, six pure oncocytic-granular renal cell carcinomas, 15 pure clear cell renal carcinomas, and two cases of mixed oncocytic-granular and clear cell heterogenous renal cell carcinomas were determined on Feulgen-stained paraffin sections using the (CAS-200 image Analyzer). All five renal oncocytomas were diploid, as were six oncocytic-granular renal cell carcinomas. Three of the 15 clear renal cell carcinomas were aneuploid. In one heterogeneous renal cell carcinoma, the oncocytic-granular foci were diploid and the clear cell focus was aneuploid. The other heterogeneous renal cell carcinoma was uniformly diploid. In 21 renal cell carcinomas, one of 14 stage I tumors was aneuploid, all four stages II and III tumors were diploid, and two of three stage IV cases were aneuploid. All stages I, II, and III patients were free of disease 3 to 48 months after surgery. All three stage IV cases were dead of their disease within 36 months of surgery. We conclude that DNA analysis by image cytometry best identifies the heterogeneity of ploidy patterns in mixed cell type carcinomas, generally correlates with the stage of disease, and may be of value in predicting overall prognosis of renal epithelial neoplasms. DNA analysis by image cytometry, however, did not reveal significant differences between oncocytic granular cell carcinoma and oncocytoma, since both lesions were generally diploid. The distinction between the two tumors is best made on morphologic grounds.

Adenoma↗
PubMed1992

Imaging of normal anatomy and anomalies of the brain.

Magnetic resonance imaging permits better delineation of many anatomic structures not resolved with other imaging modalities and, by permitting the behavior of these structures to be observed at different pulse sequences, allows their tissues to be characterized. The literature of the year 1990 to 1991 includes many descriptive reports of normal anatomy, some of which are accompanied by explanations for the MR signal appearance. Familiarity with normal central nervous system structures and with normal MR signal characteristics is essential to avoid mistaking them for pathologic variants.

Brain↗