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Biomedical subjects

J Stears

Publications and source records attributed to J Stears.

13 recordsLinked to original sources

Treatment of recurrent glioma with intracavitary alloreactive cytotoxic T lymphocytes and interleukin-2.

For a single-dose toxicity assessment, five patients with recurrent malignant glioma (ages 29-46 years) were treated with intracavitary alloreactive cytotoxic T lymphocytes (CTL) and interleukin-2 (IL-2). The trial tested the hypothesis that alloreactive CTL, sensitized to the major histocompatibility complex (MHC) proteins of the patient, offer selective, targeted killing of glioma cells that express MHC. Patient lymphocytes, which also express MHC, were irradiated and placed into CellMax artificial capillary systems with lymphocytes from MHC-disparate donors and CTL developed over a 2- to 3-week period with a low concentration of IL-2. The CTL largely expressed CD3 and CD11a/CD8 markers and lysed targets displaying patient MHC. CTL were implanted into the tumor bed at surgery and a catheter was used for subsequent infusions. Patients received one to five treatment cycles every other month; one cycle generally consisted of two or three CTL infusates administered within a 1- to 2-week period. Different unrelated donors were used for each cycle. Treatment was well tolerated; transient toxicity at grades 1-3 was recorded by NCI Common Toxicity Scale criteria. Two glioblastoma patients have died; one from tumor recurrence locally and the other from recurrence at a site distant from the treatment. Two of the five patients completed five cycles; one anaplastic oligodendroglioma patient shows no evidence of tumor 30 months from the start of immune therapy and an anaplastic astrocytoma patient shows stable disease 28 months after initiation of therapy. One anaplastic oligodendroglioma patient, who dropped the protocol during her second treatment cycle, has no evidence of tumor 28 months after recurrence.

Adult↗

Quantitative contrast-enhanced MR imaging of the optic nerve.

During the acute stages of optic neuritis damage to the blood-optic nerve barrier can be detected using i.v. paramagnetic contrast-enhanced MR imaging. Quantification of the enhancement pattern of the optic nerve, intraorbital fat and muscle was determined in 15 normal subjects using 3 fat-suppression MR imaging methods: T1-weighted spin-echo and spoiled gradient-echo sequences preceded by a fat-frequency selective pulse (FATSAT+SE and FATSAT+SPGR, respectively) and a pulse sequence combining CHOPPER fat suppression with a fat-frequency selective preparation pulse (HYBRID). Pre- and postcontrast-enhanced studies were acquired for FATSAT+SE and FATSAT+SPGR. There was no significant enhancement of the optic nerve by either method (mean increase of 0.96% and 5.3%, respectively), while there was significant enhancement in muscle (mean 118.2% and 108.2%, respectively; p < 0.005) and fat (mean increase of 13% and 37%, respectively; p < 0.05). Postcontrast optic nerve/muscle signal intensity ratios (mean, SD) were 0.51 (0.07), 0.58 (0.05) and 0.75 (0.05) for FATSAT+SE, FATSAT+SPGR and HYBRID, respectively. These results suggest a practical methodology and range of values for normal signal intensity increases and ratios of tissue signal that can be used as objective measures of optic neuritis for natural history studies and treatment trials.

Adipose Tissue↗

A new asymmetric screen-film combination for conventional chest radiography: evaluation in 50 patients.

OBJECTIVE: A new asymmetric screen-film combination for conventional chest radiography was evaluated by four thoracic radiologists. MATERIALS AND METHODS: Fifty chest radiographs obtained with a new asymmetric screen-film combination were compared with radiographs obtained in the same patients during the same breath-hold with a conventional system. Patients referred from the oncology service were studied because of the increased prevalence of abnormal findings on chest radiographs in this population. The differences in the quality of the images were assessed by four chest radiologists who used a direct-comparison technique. Eleven anatomic shadows that are normal on chest radiographs were assessed. Fifty abnormal findings also were compared. RESULTS: The image quality of the new asymmetric screen-film combination was judged to be superior to that of the conventional system for normal anatomy and abnormal findings (p < or = .003). CONCLUSION: The new asymmetric film consistently showed more clinically useful detail in the mediastinum and in the lung projected over the diaphragm and heart. The radiation dose was about 30% less with the new screen-film system.

Evaluation Studies as Topic↗

Patterns of pulsatile pituitary glycoprotein secretion in central hypothyroidism and hypogonadism.

Five patients with central hypothyroidism and hypogonadism due to mass or infiltrative lesions of the pituitary and hypothalamus were studied to determine pulsatile pituitary glycoprotein secretion patterns. Blood samples were obtained every 15 min over 24 h, and TSH, LH and FSH were measured by immunoradiometric assays. Hormone pulses were located by cluster analysis, and pulse patterns were compared to those in normal subjects. Three patients had unmeasurable LH levels, while two had a normal number of low amplitude pulses. In contrast, all patients had normal FSH pulse frequency, and only one had low pulse amplitude. Three patients had normal 24-h TSH pulse frequency and amplitude, while two had slightly decreased pulse parameters. However, all failed to show normal nocturnal increases in TSH pulse amplitude. Thus, anatomical hypothalamic-pituitary lesions disrupt pulsatile glycoprotein secretion in a discordant fashion. LH is most severely affected, with abnormal pulse patterns similar to those in idiopathic central hypogonadism. FSH and TSH pulses are relatively preserved, but loss of the usual nocturnal increase in TSH pulse amplitude is sufficient to cause clinical hypothyroidism. Whether these defects reflect intrinsic pituitary disease or impaired hypothalamic releasing factor function remains to be determined.

Adolescent↗

Subarachnoid space: middle ear pathways and recurrent meningitis.

Congenital bony abnormalities of the inner ear may result in a communication between the middle ear and the subarachnoid space. Patients with this anomaly often present with recurrent meningitis associated with acute otitis media or with middle ear fluid. This article presents three cases of recurrent meningitis with open middle ear--subarachnoid space connections. The first two cases involve a cerebrospinal fluid leak into the middle ear via the oval window, both patients having a Mondini-type of inner ear deformity. The pathway in the third case opened into the middle ear along the horizontal portion of the facial nerve. Computed tomography (CT) scanning with metrizamide and differential density calculations helped to identify the abnormal pathway and to confirm that the leak has been closed postoperatively. Use of the CT scanner in these cases can be helpful in planning the surgical closure and in postoperative follow-up.

Adolescent↗

Metachromatic leukodystrophy (MLD). XV. Adult MLD with focal lesions by computed tomography.

A 31-year-old woman with adult metachromatic leukodystrophy was seen for a progressive dementia. Computed tomographic scans showed four, nearly mirror-image, hypoabsorptive areas in cerebral white matter. These symmetric bifrontal and biparietal abnormalities were accompanied by mild ventricular enlargement and by a slight to moderate volume loss throughout the brain. Diffuse white-matter abnormalities of a kind that might otherwise be anticipated in the usual childhood leukodystrophy were not seen.

Adult↗

Locked-in syndrome caused by a tumor.

A case of locked-in syndrome is described. Clinical and radiologic evidence suggested the presence of a brain-stem tumor. Autopsy showed that the patient had a reticulum cell sarcoma. This is the first reported case of locked-in syndrome caused by a tumor.

Adult↗

Monitoring of visual function during parasellar surgery.

Damage to the visual system is an unfortunate complication of surgery in the area of the optic chiasm. It is now possible tomonitor the functional status of the visual system intreoperatively at regulat intervals. This is accomplished by recording the Visual Evoked Response to flashes of light from light-emitting-eiodes. These diodes are embedded in a special plastic shell which inserts under the eye lids of each eye. Since the light comes from the diodes in the plastic shell, there is no need to disturb the surgical procedure when a test run is desired. A record is obtained by averaging 100 three-per-second flashes.

Adenoma, Acidophil↗

Polytomoencephalography of the optic chiasm and adjacent structures.

The addition of polytomography considerably increases the sensitivity of pneumoencephalography. The chiasmatic area lends itself particularly well to investigation by polytomoencephalography. In a series of 28 patients, the transverse dimension of the optic chiasm ranged from 4 to 20 mm, with a mean of 18 mm. The posterior portion of the chiasm tended to be U-shaped; its anterior portion's shape was that of a dumbbell. Intrachiasmatic tumors distort and enlarge the chiasm. The diaphragma sella is also particularly well evaluated by this technique. The study is safe, reliable, and can be repeated as needed.

Adolescent↗

Focal seizures, early veins, and increased flow. A clinical, angiographic, and radioisotopic correlation.

Prominent early draining veins have been found in angiograms of four patients studied during an acute benign illness characterized by repetitive focal motor seizures and prominent postictal neurologic deficits. Concomitant intravenous radionuclide gamma camera flow and static images showed increased relative perfusion with a slight positive static uptake on the involved side. Follow-up studies showed no evidence of these abnormalities. These angiographic and radioisotopic findings probably correlate with the clinically observed cortical hyperemia as part of, or subsequent to, focal motor seizures. Alternatively, these findings suggest the possibility that vascular occlusions may be the underlying cause of the patients' illness.

Adult↗

Quality control in diagnostic radiology at Mayo Clinic.

During the past five years in the department of diagnostic radiology at Mayo Clinic, a quantitative quality control program has been developed and expanded. Its goal is to assure consistent image quality while minimizing exposure to radiation and reducing costs wherever possible. The key to the program is the collection of quantitative data, ie, each parameter is evaluated by an objective, not a subjective, measure which is accurate and repeatable even if the measurement is made by various persons. Operating levels and control limits have been established for all measurements, with the control limits set so changes are quantitatively noted before changes occur in the images presented to the diagnostic radiologists.

Hospital Departments↗