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Biomedical subjects

S Goldman

Publications and source records attributed to S Goldman.

At least 199 records · Page 11Linked to original sources
PubMed1995

Diagnostic yield of stereotactic brain biopsy guided by positron emission tomography with [18F]fluorodeoxyglucose.

The aim of the present study was to determine whether routine integration of positron emission tomography (PET) with 18F-labeled fluorodeoxyglucose (FDG) in the planning of stereotactic brain biopsy increases the technique's diagnostic yield. Forty-three patients underwent combined FDG-PET- and computerized tomography (CT)-guided stereotactic biopsy of intracranial lesions according to a previously described technique. In 36 patients, an area of abnormal FDG uptake was used to guide at least one stereotactic biopsy trajectory. A total of 90 stereotactic trajectories were performed; among them, 55 were based on FDG-PET-defined targets and 35 were based on CT-defined targets. Histological diagnosis was obtained in all patients, but six of the 90 trajectories were nondiagnostic; all six were based on targets defined by CT only. Differences between the diagnostic yield of trajectories based on FDG-PET-defined targets and those based on CT-defined targets were statistically significant in patients with contrast-enhanced lesions, but not in patients with nonenhancing lesions. These results support the view the FDG-PET may contribute to the successful management of brain tumor patients requiring stereotactic biopsy. Because no significant increase in discomfort or morbidity related to the technique was found, it is suggested that the development of similar techniques integrating PET data in the planning of stereotactic biopsy should be considered by centers performing stereotactic surgery and having access to PET technology.

Adolescent↗
PubMed1995

[Positron-emission tomography in akinetic rigidity syndrome].

Positron emission tomography (PET) is applied to the metabolic evaluation of hypokinetic disorders and particularly to the study of Parkinson's disease. PET has proved useful for a better understanding of the pathophysiology of these disorders. Several types of tracers are used for these studies: pre- and post-synaptic markers of the dopaminergic synapse and markers of the global metabolism of brain structures involved in the control of movement. The latter can be used at rest or in states of motor activation. These PET tracers have been used to test hypotheses on the aetiology and evolution of Parkinson's disease and on the pathophysiology of drug-induced side effects. PET also allows quantitative evaluation of new treatment strategies including experimental approaches such as intra-cerebral transplantation.

Brain↗
PubMed1994

Acute effect of carmustine on glucose metabolism in brain and glioblastoma.

BACKGROUND: Adjuvant chemotherapy benefits a minority of patients with recurrent glioblastoma; a critical question therefore is how to select such responders. Metabolic reaction of the tumor, studied by positron emission tomography (PET) with [18F]-fluoro-2-deoxy-D-glucose (FDG), may be a suitable test of tumor responsiveness. In an effort to evaluate their prognostic value, the early effects of carmustine on brain and recurrent glioblastoma glucose metabolism were studied. METHODS: Positron emission tomography with [18F]fluoro-2-deoxy-D-glucose was used to study 10 patients with recurrent glioblastoma before and 24 hours after a first dose of carmustine (120 mg/m2). Absolute quantification of glucose metabolism was obtained, and metabolic changes were analyzed and confronted with survival duration. RESULTS: The mean ratios of pre- to postchemotherapy values were 0.98 +/- 0.06 (range, 0.90-1.06) for the cortex and 0.97 +/- 0.06 (range, 0.89-1.09) for the white matter. There was no statistical difference between pre- and post-chemotherapy metabolism. In the glioblastoma, individual ratios of pre- to postchemotherapy values were considerably more scattered than in the nonneoplastic tissues, ranging from 0.76 to 1.51. A significant positive correlation (P < 0.002) was found between post- to pre-chemotherapy ratios of glucose metabolism and survival length. CONCLUSIONS: In patients with recurrent glioblastoma, the first administration of carmustine produces no acute change of glucose metabolism in the noninvolved cerebral tissues. Acute changes of glucose metabolism in tumor tissue in response to this treatment varied, and a hypermetabolic reaction possibly predicts longer survival.

Adult↗
PubMed1994

Frontal and parietal metabolic disturbances in unipolar depression.

The authors investigated brain glucose utilization using positron emission tomography (PET) in 12 normal volunteers and 12 unipolar unmedicated depressed patients (six endogenous; six nonendogenous) following injection of [18F]fluoro-deoxyglucose (FDG). Compared by analyses of variance, absolute and relative regional glucose metabolic rates appeared different in depressed patients and control subjects, especially in parietal and frontal lobes. In patients with unipolar depression, metabolic rates were increased in the orbital part of the frontal lobe and decreased in a frontal dorsolateral area. The metabolic supero-basal gradient calculated in the frontal cortex was significantly lower in depressed patients than in normal subjects. Decreased glucose metabolism was also observed in the parietal cortex of depressed patients. No differences in glucose metabolic rates have been detected between endogenous and nonendogenous patients. No correlation has been found between the metabolic data and the Hamilton Rating Scale.

Adult↗
PubMed1994

Effect of catechol-O-methyl transferase inhibition on peripheral and central metabolism of 6-[18F]fluoro-L-dopa.

In the presence of carbidopa, L-3,4-dihydroxy-6-[18F]fluorophenylalanine ([18F]fluoro-DOPA) is mainly metabolized by catechol-O-methyl transferase. We studied the effects of entacapone, a peripheral catechol-O-methyl transferase inhibitor, on striatal [18F]fluoro-DOPA uptake in rats. Rats were pretreated with carbidopa, entacapone or both before high specific activity (> 2 Ci/mmol) [18F]fluoro-DOPA administration. Entacapone alone antagonized the appearance of methylated metabolites in plasma, striatum and cerebellum but did not increase striatal [18F]fluoro-DOPA availability. Entacapone added to carbidopa significantly increased the striatum/cerebellum total radioactivity ratio (1.4 versus 1.2 in rats with carbidopa, 1.0 in controls) but significant levels of methylated metabolites were found in the brain. Entacapone added to carbidopa might increase the striatum/cerebellum total radioactivity ratio in humans undergoing [18F]fluoro-DOPA positron emission tomography (PET) studies. However, the appearance of methylated metabolites in the brain could hamper quantification of the PET data.

Animals↗
PubMed1994

Hypopyon uveitis in patients with acquired immunodeficiency syndrome treated for systemic Mycobacterium avium complex infection with rifabutin.

OBJECTIVE: Iridocyclitis has been identified as a dosage-dependent side effect in patients with the acquired immunodeficiency syndrome (AIDS) who are treated for Mycobacterium avium complex (MAC) infection with systemic rifabutin. We reviewed cases of acute hypopyon uveitis occurring in patients with AIDS to establish whether there was an association. DESIGN: Retrospective case series. SETTING: Outpatient clinic and inpatient hospital-based ophthalmology referral practice and infectious disease specialty service. PATIENTS: Seven patients with AIDS, aged 10 to 40 years, presenting with acute unilateral hypopyon mimicking infectious endophthalmitis. MAIN OUTCOME MEASURES: Findings from complete ophthalmological evaluation and ancillary laboratory testing. RESULTS: At the time of presentation, all seven patients were receiving treatment for MAC infection with rifabutin (dosage range, 300 to 600 mg/d) and clarithromycin. Results of microbiological investigations in five patients were negative. Iridocyclitis became bilateral in all seven patients, and hypopyon developed in the contralateral eye in five of seven patients. Hypopyon resolved rapidly with intensive topical corticosteroid therapy. Residual inflammation responded to topical corticosteroids with or without reduction of the rifabutin dosage. CONCLUSIONS: Concomitant use of rifabutin, clarithromycin, and fluconazole may precipitate hypopyon uveitis in patients with AIDS being treated for MAC infection.

AIDS-Related Opportunistic Infections↗
PubMed1994

Multicompartmental study of fluorine-18 altanserin binding to brain 5HT2 receptors in humans using positron emission tomography.

Serotoninergic type 2 (5HT2) receptors have been implicated in the regulation of many brain functions in humans and may play a role in several neurological and psychiatric diseases. Fluorine-18 altanserin has been proposed as a new radiotracer for the study of 5HT2 receptors by PET because of its high affinity for 5HT2 receptors (Ki: 0.13 nM) and its good specificity in in vitro studies. Dynamic PET studies were carried out in 12 healthy volunteers after intravenous injection of 0.1 mCi/kg [18F]altanserin. Ninety minutes after injection, we observed mainly cortical binding. Basal ganglia and cerebellum showed very low uptake and the frontal cortex to cerebellum ratio was about 3. To evaluate the quantitative distribution of this ligand in the brain, we used two different methods of data analysis: a four-compartment model was used to achieve quantitative evaluation of rate constants (K1 and k2 through k6) by non-linear regression, and a multiple-time graphical analysis technique for reversible binding was employed for the measurement of k1/k2 and k3/k4 ratios. Using both methods, we found significant differences in binding capacity (estimated by k3/k4 = Bmax/Kd) between regions, the values increasing as follows: occipital, limbic, parietal, frontal and temporal cortex. After correction of values obtained by the graphical method for the existence of non-specific binding, results generated by the two methods were consistent.

Adult↗
PubMed1994

Temporal glucose metabolism in borderline personality disorder.

The pathophysiology of borderline personality disorder (BPD) is obscure. Underlying organic factors such as epilepsy are suspected because clinical characteristics of the syndrome are similar to some manifestations of patients with complex partial seizures (CPS). Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) reveals hypometabolism in the area surrounding epileptic foci. To test the epilepsy hypothesis in BPD, we have explored 10 patients with BPD and compared them with 15 control subjects using PET with FDG. We conclude that PET provides no metabolic indication of temporal lobe epilepsy in BPD.

Adult↗
PubMed1994

Efficacy and safety of iopromide for excretory urography.

RATIONALE AND OBJECTIVES: Iopromide is a nonionic monomeric contrast agent. Initial laboratory and clinical data have shown that it is relatively safe. Efficacy for excretory urography has been shown to be good, comparable with other low-osmolality agents. The authors attempted to confirm these impressions in a randomized, double-blind comparison with equivalent doses of ioversol and iopamidol. METHODS: Two hundred adult patients undergoing excretory urography were studied. One hundred received iopromide, 40 received ioversol, and 60 received iopamidol (300 mg I/kg) as an intravenous bolus. Urographic films (obtained 1, 5, 15, and 20 minutes after the bolus, and postvoid) were interpreted by an observer blinded to contrast type. Visualization of renal parenchyma, pelvis and calyces, ureters, and bladder was independently assessed as excellent, good, poor, or nonvisualized. Vital signs were recorded before, 30 to 60 minutes after, and 24 hours after injection. Adverse reactions were sought, physical examinations were performed, and standard hematology and serum chemistry values were measured before and 1 day after injection; a 72-hour serum creatinine level was also measured. RESULTS: Ninety-eight percent of visualization scores were good or excellent; no significant differences among iopromide, iopamidol, and ioversol were found, nor were there any significant differences among groups in vital signs. Only one patient experienced a contrast-related physical examination change (subcutaneous extravasation). No significant changes with regard to hematology or serum chemistry values were observed; there was no contrast-induced nephropathy. Mild adverse reactions were experienced by 10% of patients; there were no significant differences in reaction rates among contrast agents. CONCLUSIONS: Iopromide at a dose of approximately 300 mg I/kg is safe and effective as an excretory urographic agent and is comparable in performance with ioversol and iopamidol.

Adult↗
PubMed1994

PET in stereotactic conditions increases the diagnostic yield of brain biopsy.

We have recently described a technique allowing routine integration of PET scan data in the planning of stereotactic brain biopsy [Levivier et al:, Neurosurgery, 1992; 31:792-797]. We now report our results in a consecutive series of 38 patients that underwent combined FDG-PET and CT-guided stereotactic biopsy between June 1991 and January 1993. Stereotactic procedures were performed according to a standard protocol in which two biopsy trajectories were used whenever possible. This yielded to a total of 78 trajectories. In 31 patients, at least 1 trajectory was defined using an abnormality visualized on PET. The histological diagnosis was obtained in all cases. The diagnostic yield of each trajectory according to the FDG uptake of PET and contrast enhancement on CT showed that most low-grade tumors were found in hypometabolic/hypodense areas, glioblastomas were all diagnosed in areas with increased FDG uptake and contrast enhancement on CT while data for anaplastic astrocytomas were heterogeneously distributed. In the present series, 6 targets defined on CT were nondiagnostic; this never occurred when targets were defined on FDG-PET. In one case of anaplastic astrocytoma, the diagnosis was only made using a target defined on PET in a normal CT area; the second trajectory was made in a contrast-enhanced area on CT and was nondiagnostic. Because only structural images such as CT or MRI are available preoperatively, we analyzed separately the benefit of FDG-PET-guided biopsy in patients who have either an enhanced- or a nonenhanced lesion on CT. CT-enhanced lesions were found in 27 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Quantitative two-dimensional echocardiographic measurements are major predictors of adverse cardiovascular events after acute myocardial infarction. The protective effects of captopril.

BACKGROUND: Left ventricular enlargement after myocardial infarction increases the likelihood of an adverse outcome. In an echocardiographic substudy of the Survival and Ventricular Enlargement (SAVE) Trial, we assessed whether captopril would attenuate progressive left ventricular enlargement in patients with left ventricular dysfunction after acute myocardial infarction and, if so, whether this would be associated with improved clinical outcome. METHODS AND RESULTS: Two-dimensional transthoracic echocardiograms were obtained in 512 patients at a mean of 11.1 +/- 3.2 days after infarction and were repeated at 1 year in 420 survivors. Left ventricular size was assessed as left ventricular cavity areas at end diastole and end systole and left ventricular function as percent change in cavity area from end diastole to end systole. Patients were randomly assigned to placebo or captopril, and the incidence of adverse cardiovascular events consisting of cardiovascular death, heart failure requiring either hospitalization or open-label angiotensin-converting enzyme inhibitor therapy, and recurrent infarction were determined over a follow-up period averaging 3.0 +/- 0.6 years. Irrespective of treatment assignment, baseline left ventricular systolic area and percent change in area were strong predictors of cardiovascular mortality and adverse cardiovascular events. At 1 year, left ventricular end-diastolic and end-systolic areas were larger in the placebo than in the captopril group (P = .038, P = .015, respectively), and percent change in cavity area was greater in the captopril group (P = .005). One hundred eleven of the 420 1-year survivors with 1-year echo measurements (26.4%) experienced a major adverse cardiovascular event, and these patients had more than a threefold greater increase in left ventricular cavity areas than those with an uncomplicated course. Sixty-nine patients with adverse cardiovascular events were in the placebo group compared with 42 patients in the captopril-treated group (a risk reduction of 35%, P = .010). CONCLUSIONS: Two-dimensional echocardiography provides important and independent prognostic information in patients after infarction. Left ventricular enlargement and function after infarction are associated with the development of adverse cardiac events. Attenuation of ventricular enlargement with captopril in these patients was associated with a reduction in adverse events. This study demonstrates the linkage between attenuation of left ventricular enlargement by captopril after infarction and improved clinical outcome.

Captopril↗
PubMed1994

Long-term graft patency (3 years) after coronary artery surgery. Effects of aspirin: results of a VA Cooperative study.

BACKGROUND: The long-term success of coronary bypass surgery is dependent on graft patency after surgery. This trial was designed to determine if aspirin improved saphenous vein graft or internal mammary artery (IMA) graft patency between 1 and 3 years after coronary artery bypass grafting (CABG). METHODS AND RESULTS: After receiving aspirin 325 mg/d for 1 year after CABG and undergoing a 1-year postoperative cardiac catheterization, patients were randomized to receive either aspirin (325 mg) or placebo for 2 additional years. Angiography was performed 3 years after surgery to determine the primary end point-saphenous vein graft patency in 288 patients and IMA graft patency in 167 patients. At 3 years after CABG, the saphenous vein graft occlusion rate was 17.0% (62 of 365) for patients treated with aspirin compared with 19.7% (74 of 376) for those who received placebo (P = .404). For saphenous vein grafts that were patent at 1 year, the occlusion rate at 3 years was 4.8% (15 of 313) for patients treated with aspirin compared with 4.2% (13 of 310) for patients who received placebo (P = .757). At 3 years, the IMA graft occlusion rate was 10.3% (8 of 78) for patients treated with aspirin compared with 7.9% (7 of 89) for patients who received placebo (P = .594). For IMA grafts that were patent at 1 year, the occlusion rate was 4.3% (3 of 70) for patients treated with aspirin compared with 2.5% (2 of 81) for patients who received placebo (P = .541). CONCLUSIONS: These data suggest that aspirin treatment does not improve saphenous vein graft or IMA graft patency between 1 and 3 years after CABG.

Aspirin↗
PubMed1994

[The Kibbutz physician: family medicine theory in practice].

124 of 251 physicians living and working in 109 of the 194 kibbutzim in Israel answered a 125-item postal questionnaire on their professional and personal characteristics and the special issues affecting a kibbutz physician. Most were specialists in family practice, had had the best of modern medical training, were deeply involved in their communities, and were familiar with all aspects of their patients' lives. They were given the opportunity to express the bio-psycho-social model of family medicine. This study relates to the special encounter of family medicine theory and its practice in the kibbutz system of health care delivery, including the problems of the kibbutz physician and the degree of personal satisfaction derived.

Family Practice↗
PubMed1994

Carbon-11-methionine and fluorine-18-FDG PET study in brain hematoma.

Three patients were examined using PET with L-methyl-11C-methionine (11C-methionine) and 2-18F-fluoro-2-deoxy-D-glucose (FDG) 20 to 32 days after the occurrence of nontumoral brain hematomas. PET revealed high uptake of 11C-methionine in the area surrounding the hematoma in all three patients. In two patients, discrete spots of moderate uptake of FDG were found at the periphery of a hypometabolic area. PET studies were repeated in two patients 76 and 103 days after the bleeding, respectively, and showed a dramatic decrease in 11C-methionine uptake around the hematoma. The spots of FDG uptake disappeared on the repeated late scans. We hypothesize that the subacute gliotic reaction surrounding brain hematomas is responsible for increased uptake of 11C-methionine and for the presence of spots of FDG uptake. PET studies with 11C-methionine and FDG performed 20 to 32 days after the initial symptom are not helpful in the differentiation between neoplastic and non-neoplastic origins of an intracerebral hemorrhage since tracer uptake at the periphery of the lesion may be increased in both.

Acute Disease↗
PubMed1994

Identification of simple substituted phenols with thyromimetic activity: cardiac effects of 3,5-diiodo-4-hydroxyphenylpropionic acid.

To define the minimal structural requirements for cardiac activity of thyroid hormone analogs, a series of substituted phenols were screened for their ability to bind bacterially expressed thyroid hormone receptors. Compounds with binding activity then were tested for their ability to induce expression of alpha-myosin heavy chain mRNA in primary cultures of fetal rat cardiomyocytes, a sensitive marker for potential inotropic activity. 3,5-Diiodo-4-hydroxyphenylpropionic acid (DIHPA) was found to bind specifically to bacterially expressed alpha-1 and beta-1 thyroid hormone receptors (Kaff approximately 1 to 2 x 10(5) M-1) and to induce alpha-myosin heavy chain (EC50 approximately 5 x 10(-7)). To assess the effects of DIHPA on cardiac performance in vivo, hemodynamic measurements were made in three groups of hypothyroid rats treated for 5 days with s.c. doses of DIHPA (15 mg/100 g), L-thyroxine (T4, 1.5 micrograms/100 g) or saline. Compared to controls, DIHPA and T4 produced increases in heart rate, left ventricular +dP/dtmax, -dP/dtmax, and isovolumic relaxation. In isometric papillary muscles preparations, DIHPA and T4 shortened time-to-peak tension and time-from-peak tension to 50% decline as compared with saline-treated controls. Muscles from both drug-treatment groups showed similar responses to graded doses of isoproterenol (10(-8) to 10(-3) M) and to variations in Ca++ concentration of the muscle bath (0.3125 to 3.75 x 10(-3) M). Thus, DIHPA is a novel thyromimetic compound with effects on myocardial function similar to those observed with T4.

Animals↗
PubMed1994

[Cerebral lesions following convulsive partial status epilepticus. Clinical, neuroradiologic and PET study of a case].

An 11-year-old girl developed signs of intracranial hypertension after status epilepticus with convulsive movements of her right upper limb. Computerized tomography revealed left hemispheric hypodensity with mass effect, attributed to vasogenic edema. Intracranial hypertension was controlled under intracranial pressure monitoring and clinical status slowly improved. The patient was aphasic and right hemiplegic when she recovered consciousness but she remarkably recovered from her neurological deficits during the following two years despite neuroradiological evolution demonstrating extensive destruction of the left cortex and white matter. Two positron emission tomography (PET) scans were performed respectively six weeks and eight months after status epilepticus, and both demonstrated profound left hemispheric hypometabolism except in the lenticular nucleus and a restricted area of motor/premotor cortex. On the other hand, glucose metabolism in the right hemisphere was heterogeneously increased on the second PET when compared with the first PET. We concluded that, in this case, clinical recovery might have implicated functional reorganization arising from the intact hemisphere.

Aphasia↗
PubMed1993

The pain drawing and Waddell's nonorganic physical signs in chronic low-back pain.

Pain drawings were obtained from a group of 651 patients who had chronic low-back pain. Pain drawings were rated in four grades according to the degree of organic and nonorganic pain. Experienced and inexperienced evaluators were used. The reliability was excellent with an interevaluator reliability between 73% and 78%. A correlation between pain drawings and Waddell's nonorganic physical signs demonstrated that a large proportion of patients with high Waddell scores had nonorganic pain drawings. No significant differences were noted in the distribution of Waddell scores and pain drawings based on patient gender or payment status (i.e., medicolegal or workers' compensation). Pain drawings afford an important adjunct in the physician's assessment of chronic low-back pain.

Female↗