Biomedical subjects
A Lieberman
Publications and source records attributed to A Lieberman.
Treatment of Parkinson's disease with dopamine agonists: a review.
Bromocriptine and lergotrile were administered to 81 patients with Parkinson disease (PD) and increasing disability despite optimal treatment with levodopa (secondary levodopa failures). Sixty-six patients were treated with bromocriptine and 53 patients were treated with lergotrile. Both groups had significantly decreased rigidity, tremor, bradykinesia and gait disturbance upon addition of bromocriptine or lergotrile to levodopa. Twenty-five patients improved at least one-stage on bromocriptine, and 21 improved at least one-stage on lergotrile. The mean dose of bromocriptine was 47 mg, and the mean dose of lergotrile was 49 mg, permitting a 10% reduction in levodopa. Bromocriptine was discontinued in 29 of 66 patients because of adverse effects, including mental changes (14 patients) and involuntary movements (9 patients). Lergotrile was discontinued in 33 of 53 patients because of adverse effects including hepatotoxicity (11 patients) and mental changes (12 patients). The results of treatment with bromocriptine or lergotrile were comparable, with patients either responding or not. Bromocriptine will shortly be available for use in PD. Lergotrile, because of the hepatotoxicity, will not.
Irreversible pulmonary toxicity after single course of BCNU.
Irreversible pulmonary interstitial fibrosis developed 36 days after a single course of BCNU (total, 400 mg) in a patient with a malignant brain tumor. The case is unique in that irreversible changes developed shortly after a single course of BCNU whereas heretofore such permanent changes have been associated only with multiple courses of the drug (2,000-4,000 mg). This suggests that individual differences in the local sensitivity of lung tissue may be as important as the dose of the drug in determining whether irreversible fibrosis will develop.
Sarcoma arising in oligodendroglioma of the brain.
A case is reported of a tumor composed of both oligodendrogliomatous and sarcomatous elements. The interpretation is offered that the sarcoma arose secondarily by neoplastic transformation of the hyperplastic blood vessels formed in response to the presence of the oligodendroglioma. This tumor may be considered analogous to the astrocytoma-sarcoma, which is much more common, and to the metastatic carcinoma with secondary sarcoma, of which one case has been reported.
Cerebral arteritis in scleroderma.
Central nervous system (CNS) involvement is rare in scleroderma unless there are concomitant abnormalities in renal or lung function or malignant hypertension. A 43-year-old woman with typical scleroderma developed subacute encephalopathy despite absence of the above abnormalities. Cerebral angiography demonstrated a focal arteritis. The patient improved while being given corticosteroids. We believe this case indicates that cerebral arteritis can occur in scleroderma.
Directional Doppler in occlusive cerebrovascular disorders.
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Intracranial hemorrhage and infarction in anticoagulated patients with prosthetic heart valves.
In 1 year 6 patients with prosthetic heart valves (PHVs) treated with anticoagulants suffered intracranial hemorrhage. In 4, hemorrhage occurred into the site of a recent non-hemorrhagic infarction. In the others, both of whom had endocarditis, hemorrhages probably occurred as the result of rupture of a mycotic aneurysm. Five patients were treated with warfarin, 1 with heparin. In all patients the level of anticoagulant activity was greater than 1.5 times control. Five patients were in atrial fibrillation; 1 was hypertensive. The diagnosis of intracranial hemorrhage was made and its location and extent accurately determined by computed tomography (CT). Three patients underwent surgery and 2 are alive with only minor neurological deficits. Among the 3 patients who did not undergo surgery 2 died and 1 is alive with a moderate neurological deficit. The management of PHV patients with use of anticoagulants is discussed in terms of the mechanisms involved in intracranial bleeding. Emphasis is placed on prevention of emboli, discontinuation of anticoagulants once non-hemorrhagic infarction has occurred and the primacy of CT scan in diagnosis when hemorrhage is suspected. The special problems of anticoagulation in the presence of endocarditis are also discussed.
Clinical study of fetal mesencephalic intracerebral transplants for the treatment of Parkinson's disease.
This study reports our findings from 22 patients (ages ranging from 42 to 73 yr; mean = 55.2) with recalcitrant idiopathic Parkinson's disease (PD) who received implants of fetal ventral mesencephalic tissue using an MRI-guided stereotactic procedure and who have been followed for at least 6 mo postoperatively, employing the guidelines established by the Core Assessment Program for Intracerebral Transplantations. Evaluations were videotaped and were performed both on and off levodopa medications. To date, we have seven patients with 24 mo, three with 18 mo, three with 12 mo, and nine with 6 mo post-surgical assessments. Comparing surgical outcomes to levels prior to fetal transplants we found: 1) mean levodopa levels were reduced 46% at 6 mo, 12% at 12 mo, 20% at 18 mo, and 54% at 24 mo; 2) Unified Parkinson's Disease Rating Scale (UPDRS) scores with patients on levodopa were improved by an average of 38% (6 mo), 50.2% (12 mo), 69.3% (18 mo), and 73.9% (24 mo), while off medication scores showed reductions ranging from 24.7% at 6 mo to 55.1% at 24 mo. Other measures, including Hoehn-Yahr staging, Activities of Daily Living, and dyskinesia rating scales, were also significantly improved following fetal transplants. Timed motor tasks (finger dexterity, supination-pronation, foot tapping, and Stand-Walk-Sit) performance also demonstrated highly significant improvements. Patient's self-rating scores indicated that the patients typically perceived substantial improvements in their condition. However, substantial variability in the improvements following surgery still persists and range from nominal improvements in performance to significant changes that can be classified as altering the overall lifestyle of the patients. To date, 4 of the 22 subjects were considered by the physicians to be nonresponders; that is, there were no clinically relevant improvements in these patients' conditions.
Microprocessor controlled particle counter system.
Operation of an optical particle counter with microprocessor control of particle size calibration and data recording is described. Sensors are available to measure particles 0.1 micron and larger. A system with a range from 2 microns to 125 microns will be described. Calibration data based on response to monosized particles are stored in the system memory, along with sensor resolution information and system changes since the last calibration. The instrument adjusts the particle size channels internally for the selected calibration base particles. Once calibrated, the instrument can be set to report data in operator selectable sizes or any of four default particle size groups. Three default groups are based on pharmaceutical and hydraulic fluid power industry standards and one is set in a logarithmic spread of 16 particle sizes that covers the system dynamic range. A front-panel keyboard and CRT display allow selection and control of all operating parameters. These include reported size ranges, liquid sample size, number of sample replications (including suspect sample rejection), data averaging, and comparison of data from two sensors. Differential or cumulative data can be reported in tabular or histogram format. Data can be sent to an internal thermal printer or to an RS-232C output.
A new coincidence model for single particle counters, Part II: Advances and applications.
Accuracy, acceptance limits and methods for U.S.P. (788) contaminating particle assays published in the XXII Revision are refined in U.S.P. XXIII. In both Revisions, although different numerical values and methods are employed, particle contamination limits remain constants for all S.V.I. container volumes. The effect of this quality standard is high particle concentration acceptance limits in the smallest S.V.I. container sizes. The effect of these high concentrations is to introduce both undercount errors and false counts into U.S.P. (788) SVI contaminating particle assays. There is general agreement that the count of high concentrations of particles by a single particle light extinction counter result in an increase of the average size of the distribution of particles reported and a decrease in their total number. The error mechanism is termed "signal coincidence." Understanding and control of both these problems is unified with the introduction of the count efficiency parameter. Part I of this paper makes available two core concepts with which evaluation and control of coincidence error in single particle counters can be accurately quantified. These two core concepts are the "Particle Triggered Poisson Model," a new more accurate statistical model of the particle counting process and a concentration measure that includes the effect of particle size on the counting capability of a detector. Use of these concepts make it possible to evaluate particle detector count efficiency capability from experimental data of the coincidence effect. This is an application paper. It combines the theory in the Part I paper with the replicability of particle counters into a simple test protocol. The test results can be used to calculate a contour of particle size and count within which both undercount errors and the introduction of false counts into U.S.P. (788) particle assays are controlled. From the data analyzed it can be seen that any single particle size test cannot effectively evaluate detector performance. The use of the theory and methodology described can help realize the intent of the U.S.P. (788) SVI particle contamination assay.