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Biomedical subjects

J R Perry

Publications and source records attributed to J R Perry.

At least 37 records · Page 2Linked to original sources
PubMed1996

Magnetic resonance imaging of cranial nerve VII.

Magnetic resonance imaging (MRI) is well suited for the evaluation of lesions of the seventh cranial (facial) nerve. The preferred MRI approach requires use of multiplanar thin sections of the full course of the nerve from the pons through to its terminal branches on the face. The use of paramagnetic contrast greatly increases the sensitivity of MRI and for the most part precludes the need to use computed tomography scans in conjunction with the MRI scans.

Cranial Nerve Neoplasms↗
PubMed1995

Clinicopathologic features of primary and postirradiation cerebral gliosarcoma.

BACKGROUND: Gliosarcoma is an uncommon malignant brain tumor with mixed glial and mesenchymal elements. Experience is limited to case series, and pathologic data are disparate, leading to uncertainty about clinical features, management, and histogenesis. METHODS: A clinicopathologic review of 32 patients with survival analysis and immunohistochemical studies was performed including glial fibrillary acidic protein analysis, alpha-1-antitrypsin (alpha-1-AT) analysis, and smooth muscle actin (SMA) analysis. RESULTS: Twenty-five patients had primary gliosarcoma, whereas 7 developed gliosarcoma after irradiation for glioblastoma multiforme (GBM). Clinical features were similar to those of GBM. Most tumors were intraaxial and diffusely infiltrating by radiologic studies and at surgery. Median survival for primary gliosarcoma was 25 weeks overall, with patients who received irradiation surviving longer (46 vs. 13 weeks, P < 0.025). Gliosarcoma occurring after irradiation appeared hyperdense by computed tomography in five of seven cases, and median survival was 53 weeks. Primary gliosarcoma was a dimorphic tumor with malignant glial elements and features of malignant fibrous histiocytoma (MFH) or fibrosarcoma and one osteosarcoma. Smooth muscle actin labeled tumor vessels heavily, but in 15/25 primary cases, it extended to the surrounding spindle cells. The remaining cases appeared morphologically like MFH and tended to be positive for alpha-1-AT. Postirradiation gliosarcoma was fibrosarcomatous with positive SMA in 75% of the cases examined. CONCLUSIONS: Gliosarcoma behaves clinically like GBM, and survival may be improved by cranial irradiation of selected patients. Smooth muscle actin reactivity in sarcomatous areas suggests histogenesis in some tumors from the smooth muscle within GBM, whereas others may arise via different mechanisms including differentiation from a pluripotential precursor. Transformation of the smooth muscle within GBM may have therapeutic implications for antiangiogenesis agents.

Actins↗
PubMed1995

Comparison of planar, SPECT, and 3-D synthetic reprojection images. A case study.

A case study is presented in which three types of images from a Ga-67 study are compared. The Ga-67 study was performed on a patient with fever of unknown origin (FUO). Planar and SPECT images were obtained. Planar data were presented as standard 2-D images on radiographic film. The SPECT data were used to generate two sets of images: standard 2-D multiple 'slice' images presented on radiographic film and a rotating 3-D synthetic reprojection displayed on a computer monitor. Compared to the planar and SPECT images, three sites of inflammation and the path of an oblique sinus tract were best seen in the 3-D synthetic reprojection. Recognition of anatomic structures and their spatial relationships was most readily apparent when viewing the 3-D synthetic reprojection, and this method of display facilitated the rapid recognition of abnormal findings.

Adult↗
PubMed1995

Interpretation time of serial chest CT examinations with stacked-metaphor workstation versus film alternator.

PURPOSE: Interpretation time of serial staging chest CT cases, which each contained current and previous examinations, with a simple prototype workstation called filmstack was experimentally compared with interpretation time with a film alternator. MATERIALS AND METHODS: The filmstack displayed a "stack" of sections for each examination; user controls allowed rapid selection of preset attenuation windows and both synchronized and unsynchronized scrolling. Eight radiologists were timed as they used the filmstack and the film alternator to interpret four ergonomically complex serial CT cases. RESULTS: All reports dictated on the basis of findings with filmstack and film were of acceptable clinical accuracy. The time to examine a case with filmstack was significantly faster than the time with film, including the time to load and unload the alternator (99% confidence [P = .01]). There was no statistically significant difference in interpretation time between filmstack and prehung film. CONCLUSION: Use of a low-cost stacked CT workstation with a single 1,024 x 1,024 monitor is an effective means of interpreting cases that require comparison of multiple CT examinations.

Computer Systems↗
PubMed1994

Magnetic resonance imaging of nerve root inflammation in the Guillain-Barré syndrome.

We report gadolinium-enhancing nerve root lesions in a 52-year-old man with typical Guillain-Barré syndrome (GBS). This enhancement correlates well with the perineurial inflammatory and demyelinating processes known to characterize GBS and other inflammatory neuropathies. MRI should enable further exploration of patterns of disease in GBS and, with further study, perhaps assist in evaluating therapy.

Cauda Equina↗
PubMed1994

Complications of sural nerve biopsy in diabetic versus non-diabetic patients.

We compare complications from 66 sural nerve biopsies in 41 patients with diabetic peripheral neuropathy to 40 patients with neuropathy from other causes, using a retrospective telephone survey. Diabetic patients were followed for a mean of 6.8 years and non-diabetics for 5.6 years. Mild long-term pain was described by 18.9% of patients overall with no difference between groups. Mild persistent sensory symptoms, insufficient to interfere with daily activity or warrant medical therapy, were reported by 63.6% of diabetic and 27.5% of non-diabetic patients (p < 0.006). Wound infection and severe pain were uncommon in both groups and no different in diabetics. Significant complications of sural nerve biopsy occurred no more frequently in diabetic than in non-diabetic patients. While sural nerve biopsy plays no role in the routine evaluation of diabetic peripheral neuropathy, it may be performed without increased risk when indicated in these patients to exclude other causes of neuropathy and in the context of research trials.

Biopsy↗
PubMed1994

Isolation and characterization of a Saccharomyces cerevisiae peptide transport gene.

We have cloned and characterized a Saccharomyces cerevisiae peptide transport gene (PTR2) isolated from a genomic DNA library by directly selecting for functional complementation of a peptide transport-deficient mutant. Deletion and frameshift mutageneses were used to localize the complementing activity to a 3.1-kbp region on the transforming plasmid. DNA sequencing of the complementing region identified an open reading frame spanning 1,803 bp. The deduced amino acid sequence predicts a hydrophobic peptide consisting of 601 amino acids, having a molecular mass of 68.1 kDa, composed in part of 12 hydrophobic segments, and sharing significant similarities with a nitrate transport protein encoded by the CHL1 gene of Arabidopsis thaliana. Northern (RNA) hybridization experiments demonstrated a single transcript that was 1.8 kb in length and that was transiently induced by the addition of L-leucine to the growth medium. The PTR2 gene was localized to the right arm of chromosome XI by contour-clamped homogeneous electric field gel chromosome blotting and by hybridization to known chromosome XI lambda phage clones of S. cerevisiae DNA. PTR2 was tightly linked to the UBI2 gene, with the coding sequences being separated by a 466-bp region and oriented so that the genes were transcribed convergently. A chromosomal disruption of the PTR2 gene in a haploid strain was not lethal under standard growth conditions. The cloning of PTR2 represents the first example of the molecular genetic characterization of a eucaryotic peptide transport gene.

Amino Acid Sequence↗
PubMed1994

Carotid artery stenosis. Selecting candidates for surgical management.

Many patients with significant carotid artery stenosis are candidates for endarterectomy, a procedure now proved to reduce the incidence of future stroke and death. In this article, Drs Jaigobin and Perry describe an approach to patients with both symptomatic and asymptomatic carotid stenosis and review current indications for surgical referral. They also emphasize the importance of recognizing and managing concurrent coronary artery disease.

Carotid Stenosis↗
PubMed1994

Metastatic alveolar soft part sarcoma presenting as a dural-based cerebral mass.

Sarcoma metastatic to the brain is uncommon and rarely occurs as the initial manifestation of tumor. Alveolar soft-part sarcoma, a rare but well studied subtype of a soft tissue sarcoma with a propensity for central nervous system invasion, presenting with brain metastases, has been reported only once previously. We report the case of a 28-year-old man who presented with partial seizures and who was found to have a homogeneously enhancing frontal lesion on a broad dural base disclosed by computed tomography. preoperatively, the lesion was thought to be a meningioma. The tumor was excised easily and had features typical of an alveolar soft-part sarcoma, which were revealed by light and electron microscopy as well as immunohistochemical analysis. Multiple lung nodules compatible with metastases were found on a chest film. Meningeal dissemination has been reported in a variety of sarcoma types, including rhabdomyosarcoma, fibrosarcoma, and leiomyosarcoma. We add alveolar soft-part sarcoma to this list and suggest that increased recognition of the propensity for these tumors to exhibit metastatic spread to the dura should eliminate diagnostic confusion and provide an earlier diagnosis of these rare lesions. The patterns of spread in metastatic sarcoma deserve further study.

Adult↗
PubMed1993

Interpretation of CT studies: single-screen workstation versus film alternator.

A prototype single-screen workstation with a 2,048 x 2,560-pixel high-brightness monitor, 0.11-second image display time, and simple ergonomic design was compared to a conventional horizontal film alternator in diagnostic interpretation of chest computed tomography (CT) studies. Four radiologists used either the workstation or film alternator in interpretation of studies obtained in 10 patients. A counterbalanced within-subject repeated measures experimental design was used. Response times were analyzed for both methods of interpretation. Grades of excellent, acceptable, and unacceptable were assigned by a blinded "grader" to reports of the radiologists. The average time needed for an interpretation at the workstation was 5.65 minutes. No interpretations were graded unacceptable. Retrospective power analysis showed that 16 observers rather than four would have been required to show that use of the workstation was faster than the alternator. With this 95% confidence interval, the workstation interpretation time is clinically equivalent to that with the alternator. These data show that this type of workstation has practical application in interpretation of CT, magnetic resonance imaging, and ultrasound studies.

Humans↗
PubMed1993

The significance of spinal cord compression as the initial manifestation of lymphoma.

Eighteen patients with spinal cord compression caused by previously undiagnosed lymphoma were treated at our institution between 1976 and 1991. There were 14 male and 4 female patients (mean age, 58.2 years). The absence of bony involvement on radiographic images was a feature in 16 of the cases. All patients underwent laminectomy for decompression and tissue diagnosis, after which 5 underwent radiotherapy, 3 underwent chemotherapy, and 10 underwent combined-modality treatment. The functional outcome was improvement in 8 patients and no change in 10; no patient worsened after surgery. Eleven had advanced disease at diagnosis, while seven had limited disease, including three patients with localized extradural lymphoma. There were 16 cases of non-Hodgkin's lymphoma and 2 of Hodgkin's disease. Two patients had T-cell lymphoma and were among the longest survivors. DNA flow cytometry identified the low-grade tumors as diploid with very low proliferative indices, while the high-grade tumors all had high indices. At a mean observation time of 41.7 months, five patients have died of their disease, and seven remain in complete remission. Survival is markedly better than that reported for other malignant extradural tumors; however, even limited stage lymphoma can behave aggressively. Similarities in age, sex distribution, histological features, and the results of flow cytometry suggest behavior similar to extranodal lymphoma at other sites. Surgery to provide a tissue diagnosis, followed by combined radiotherapy and chemotherapy, is indicated for all cases.

Adult↗
PubMed1993

Dural cavernous hemangioma: an under-recognized lesion mimicking meningioma.

We report a 77-year-old woman who presented with partial seizures and was found to have an enhancing dural-based parietal convexity mass. The lesion enlarged on serial examination by computed tomography (CT) over a one year period. The clinical features and radiologic appearance were compatible with a pre-operative diagnosis of meningioma; however, pathologic findings were typical of a dural cavernous hemangioma. Accumulating evidence suggests that these lesions are an uncommon but distinct type of vascular malformation most often arising from the cavernous sinus, tentorium, or cerebello-pontine angle. With CT, magnetic resonance imaging and angiography, these lesions can closely resemble meningioma in terms of signal characteristics, enhancement pattern, and location. This is of importance both in the practical management of meningiomas where the diagnosis is often based on radiologic studies alone, and in clinical trials where incorrect entry diagnosis should be avoided.

Aged↗
PubMed1993

Dementia in general practice: the practical consequences of a more positive approach to diagnosis.

General practitioners are often reluctant to administer brief cognitive tests, and to question the relatives of patients who appear to be demented, for fear of causing distress. Diagnoses of dementia are therefore often based on guesswork, and non-demented patients may be rated as cognitively impaired in error. A randomly selected sample of 174 general practice patients aged 80 years and over were asked to complete a simple test of orientation and information in order to assess the usefulness and acceptability of such a procedure. If patients scored 10 points or less out of 12, a relative or other knowledgeable informant was questioned about their changes in mental state and behaviour. Assessments proved acceptable to patients, relatives and doctors; diagnoses were revised in 29 cases; and practical initiatives were proposed in 15 cases. Open discussions with patients and their families proved innocuous and have much to commend them.

Aged↗