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Biomedical subjects

A Fischman

Publications and source records attributed to A Fischman.

17 recordsLinked to original sources
PubMed2000

2. Diagnostic Utility of FDG-PET in the Clinical Management of Patients with Suspected Recurrent Pancreatic Carcinoma after Whipple Procedure.

Purpose: We evaluated the usefulness of FDG-PET in the assessment of patients with suspected pancreatic carcinoma who have previously undergone a Whipple procedure.Methods and Materials: Attenuation-corrected FDG-PET was performed in 11 patients (5 males, 6 females, age range 52-76 years), with suspected recurrent pancreatic carcinoma after Whipple procedure. Recurrence was suspected based on clinical, laboratory (CA19-9 serum tumor marker level), or abdominal CT findings. Diagnostic validation was by histology in 2 patients and radiologic or clinical follow-up (5 to 48 months) in 9 patients. Changes in therapeutic management that were prompted by PET were tabulated.Results: PET was concordant with the findings of abdominal CT in 7 patients (6 true-positive, 1 true-negative). PET detected unsuspected lung lesions in 1 of these patients that was subsequently confirmed by a chest CT. PET was discordant with abdominal CT in 4 patients. PET detected tumor recurrence in 3 of 4 patients in this group (27% of total) who had non-diagnostic CT and elevated CA19-9 serology. Chemotherapy was initiated in 2 of these 3 patients (18% of total), while the other patient died shortly after the PET study from pneumonia and recurrent tumor was confirmed at autopsy. The remaining 1 of 4 patients in the discordant group had a false-positive PET study due to relatively high FDG localization in a displaced loop of bowel.Conclusion: PET is useful in localizing the tumor in post-Whipple patients with suspected recurrent pancreatic carcinoma and can impact their clinical management.

Journal Article↗
PubMed1999

Enhancement of fluid filtration across tumor vessels: implication for delivery of macromolecules.

Cancer therapies using genes and other macromolecules might realize their full clinical potential if they could be delivered to tumor tissue in optimal quantities. Unfortunately, the compromised circulation within tumors poses a formidable resistance to adequate and uniform penetration of these agents. Previously, we have proposed elevated interstitial fluid pressure (IFP) as a major physiological barrier to delivery of macromolecules. Here we postulate that modulation of tumor microvascular pressure (MVP) and associated changes in IFP would enhance macromolecular delivery into a solid tumor. To test our hypothesis, we altered tumor MVP by either periodic injection or continuous infusion of angiotensin II (AII) and measured the resulting changes in IFP and uptake of macromolecules. We used the nicotinyl hydrazine derivative of human polyclonal IgG (HYNIC-IgG) as a nonspecific macromolecule and CC49 antibody as a specific macromolecule. We found that both chronic and periodic modulation of tumor MVP enhances transvascular fluid filtration, leading to a 40% increase in total uptake of the specific antibody within 4 hr of its administration. Conversely, neither continuous nor periodic infusion of AII induced any increase in uptake of nonspecific antibodies. Strategies to improve delivery of macromolecules and limitations of this approach are identified.

Animals↗
PubMed1999

Paroxysmal non-kinesigenic dyskinesia: pathophysiological investigations.

The paroxysmal dyskinesias constitute a heterogeneous group of disorders whose pathophysiologies and nosologies are still generally unknown. In a boy with severe, paroxysmal non-kinesigenic dyskinesia (PNKD), an invasive video-electrographic study demonstrated that his PNKD did not originate from the cortex, while a discharge was registered from the caudate nuclei. An 18FDG PET scan failed to show metabolic anomalies. A 18FDOPA and a 11C raclopride PET scans revealed a marked reduction in the density of presynaptic dopa decarboxylase activity in the striatum, together with an increased density of postsynaptic dopamine D2 receptors. These findings may suggest a chronic upregulation of postsynaptic dopa receptors, either because of an increase in their numbers or changes in their affinity. It remains unknown if these are secondary to reduced dopamine synthesis or altered release, or if the changes in striatal dopamine receptor binding are a primary or a compensatory mechanism.

Adolescent↗
PubMed1995

Use of magnetic resonance imaging and positron emission tomography in the assessment of synovial volume and glucose metabolism in patients with rheumatoid arthritis.

OBJECTIVE: To measure the anatomic and physiologic changes in the synovium of patients with active rheumatoid arthritis (RA) before and after the initiation of treatment with low-dose systemic glucocorticoids and methotrexate (MTX). METHODS: Two patients with RA with active synovitis involving the carpus were evaluated by imaging parameters at baseline and again after 14 weeks (of treatment with low-dose prednisone and MTX). Standard clinical parameters, laboratory measurements, and contrast-enhanced magnetic resonance imaging (MRI) (synovial volume estimate) and positron emission tomography (PET) with 18F-fluoro-2-deoxyglucose (18-FDG) (synovial metabolism estimate) were performed. RESULTS: Compared with baseline, standard clinical parameters (i.e., joint count, joint index, morning stiffness, global assessments of arthritis activity, and erythrocyte sedimentation rate) improved dramatically in both patients after treatment with low-dose prednisone and MTX. In concert with this trend, the synovial volume of the affected wrist was reduced by 60%, and 76% and the metabolism of 18-FDG was reduced by 66% and 69% in the 2 patients. CONCLUSION: These preliminary observations indicate that a volumetric estimate of inflamed synovium (using contrast-enhanced MRI) and quantification of synovial deoxyglucose metabolism (using PET) are technically feasible and, in the 2 reported cases, correlate well with standard outcome measures. These imaging modalities may provide new objective parameters to determine RA disease activity and effectiveness of antirheumatic medications; however, the potential clinical utility of these measures remains to be defined.

Arthritis, Rheumatoid↗
PubMed1991

Susceptibility contrast imaging of cerebral blood volume: human experience.

Magnetic resonance (MR) can offer a unique window on the structure/function relationships in the brain, by utilizing the established link between tissue function, metabolism, and hemodynamics. This report focuses on recent applications of MR-based cerebral blood volume (CBV) imaging in humans. Our methodology uses high-speed "single-shot" or echo planar imaging techniques, which provide the necessary temporal resolution for mapping the rapid cerebral transit of contrast agents. These MR CBV mapping techniques have been used to study normal human brain task activation and in the clinical study of patients with brain tumors. In the latter, positron emission tomography imaging was used for functional metabolic and CBV correlation. Susceptibility contrast CBV imaging should allow us to improve our understanding of the relationship between the detailed physiology and morphology of the microvascular bed and functional attributes of the brain. These techniques can be applied to understanding fundamental questions of cognitive neuroscience and can aid in improving diagnostic sensitivity and specificity in various neuropathologies.

Brain↗
PubMed1990

Salt and blood pressure in Rio Grande do Sul, Brazil.

A 1978 survey of 4,565 people in Rio Grande do Sul obtained interview and blood pressure data as well as casual urine specimens for subsequent sodium and creatinine titrations. Data derived from this survey have demonstrated a variety of complex relationships between blood pressure and sodium, a number of which are examined here. The main conclusion is that observed blood pressure differentials could reflect the kidney's ability to handle sodium, an ability subject to the influences of age, heredity, and the environment. As a consequence, it is suggested that the adoption of salt restriction by populations could bring them large health benefits.

Adult↗
PubMed1987

Primary hyperparathyroidism, hypercalcemia, paranoid delusions, homicide, and attempted murder.

This report describes a case of primary hyperparathyroidism in a 68-year-old man. The endocrine disorder, while suspected before the commission of homicide and attempted murder, was proven biochemically and histologically a number of months after the commission of the crimes. The acts of homicide and attempted murder followed the development of paranoid delusions, which rapidly resolved upon successful removal of a single cystic parathyroid gland adenoma. The unusual events that immediately followed the acts of violence indicate that the delusions occurred in a clear sensorium (absence of delirium). Psychological measures taken before and after surgery document improvement in subtle organic functioning while intelligence was unchanged. This report discusses the neuropsychiatric manifestations of hypercalcemia and reviews the literature.

Adenoma↗
PubMed1968

A new whole-scolex complement-fixation test for hydatid disease.

The sensitivity of indirect agglutination tests for the diagnosis of human hydatid disease, although high, is not sufficient. Furthermore, the general use of hydatid fluid as antigen is responsible for some false positive reactions. Scolex extracts have been shown to increase specificity, but less attention has been paid to whole-scolex antigens. The author describes a new whole-scolex complement-fixation test that, like other scolex tests, is more specific than tests using fluid antigen. Its sensitivity is at least equal to that of the hydatid fluid latex-agglutination test, and is higher than that of the fluorescent-antibody, the scolex extract latex, and the hydatid fluid complement-fixation tests.The new test is also of interest since particulate antigens are uncommon, compared with soluble antigens, in complement-fixation techniques.

Antigens↗