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Biomedical subjects

D Levine

Publications and source records attributed to D Levine.

At least 37 records · Page 2Linked to original sources
PubMed2001

Remote sonographic interpretation using a laser printer network: system performance and diagnostic accuracy in actual clinical practice.

OBJECTIVE: The purpose of our study was to evaluate the technical and clinical performance of remote sonographic interpretation using a laser printer network connecting a community-based imaging center and an academic medical center. SUBJECTS AND METHODS: During a 3-month period, 161 consecutive sonographic examinations were performed at a community-based imaging center and all 161 patients were enrolled in the study. Seventy-one (44%) of 161 examinations were interpreted on-site at the community-based imaging center, and 90 (56%) of 161 were transmitted over a T-1 line to an academic medical center where the static images were interpreted remotely. For the purposes of this study, the examination time was defined as the interval from the time the technologist started to scan the patient to the time the patient was dismissed from the radiology department. Examination times were recorded for each patient. Follow-up was available for 92 (57%) of 161 studies. Sensitivity and specificity for studies interpreted at the community-based imaging center and at the academic medical center were calculated. RESULTS: The mean examination time for pelvic sonographic examinations interpreted at the academic medical center (43 min) was significantly longer than for scans interpreted at the community-based imaging center (31 min) (p < 0.01). However, no significant difference was noted in the examination time for abdominal sonography. For all examinations interpreted on-site at the community-based imaging center for which follow-up was available, the sensitivity and specificity were 95% and 100%, respectively. For all examinations interpreted remotely at the academic medical center for which follow-up was available, the sensitivity and specificity were 93% and 90%, respectively. No significant difference was seen in the sensitivity (p = 1.00) or specificity (p = 0.24) of studies interpreted on-site versus remotely. CONCLUSION: Static sonographic images can be interpreted remotely without loss of sensitivity, but with decreased specificity. However, more time must be allotted for performing pelvic sonography when these examinations are to be interpreted remotely.

Abdomen↗
PubMed2001

Organizing posterior fossa hematomas simulating developmental cysts on prenatal imaging: report of 3 cases.

OBJECTIVE: We encountered 3 organizing tentorial hematomas simulating posterior fossa lesions such as Dandy-Walker, dermoid, or arachnoid cysts. We sought to correlate the clinical and pathologic features that allow distinction of developmental cysts from hematomas in the posterior fossa on imaging. METHODS. Prenatal sonograms in all fetuses and fetal magnetic resonance scans in 2 of the 3 were reviewed. One case proceeding to term had serial imaging up to age 11 months. Two cases had complete neuropathologic evaluation after termination. Maternal records were reviewed. RESULTS: In each case, the ultrasonographic findings were reminiscent of a developmental cyst but with echogenic debris, a rim, or both. Magnetic resonance imaging suggested tentorial hemorrhage in 2, 1 also with falcine hemorrhage. Serial prenatal and postnatal imaging showed resolution in the surviving case. Pathologically, 2 fetuses had organizing tentorial hematomas causing brain displacement. Calcifications, white matter damage, germinal matrix hemorrhage, and brain stem necrosis were also present. One mother had von Willebrand disease. CONCLUSIONS: Tentorial hematomas, with or without maternal coagulopathy, should be considered in the prenatal ultrasonographic diagnosis of cystlike posterior fossa abnormalities containing echogenic material. Fetal magnetic resonance imaging can suggest blood products. Hypoxic-ischemic brain damage may be concurrent; however, resolution of the hematoma, with no apparent neurologic sequelae, can occur.

Adult↗
PubMed2000

Novel electrostatic attraction from plasmon fluctuations

In this Letter, we show that, at low temperatures, zero-point fluctuations of the plasmon modes of two mutually coupled 2D planar Wigner crystals give rise to a novel long-range attractive force. For the case where the distance d between two planar surfaces is large, this attractive force has an unusual power-law decay, which scales as d(-7/2), unlike other fluctuation-induced forces. Specifically, we note that its range is longer than the "standard" zero-temperature van der Waals interaction. This result may, in principle, be observed in bilayer electronic systems and provides insight into the nature of correlation effects for highly charged surfaces.

Journal Article↗
PubMed2000

Indications for pelvic sonography-Do patients and doctors agree?

PURPOSE: Often, it seems that the patient history provided by the referring clinician on the sonography requisition form differs from that given by the patient during the sonographic examination. Because such a discrepancy in the history may delay the scan and disrupt the daily work flow while the referring clinician is contacted for clarification, we sought to document the incidence and cause of such discrepancies at our institution. METHODS: During a 3-month period, all outpatients who were referred for a pelvic sonographic examination were asked to indicate their understanding of why the examination had been requested. The health care providers' reasons for requesting sonography were recorded using a computer order entry system. Each pair of responses (health care provider and patient) were classified as either concordant or discordant. Patient and physician characteristics were fit into a logistic regression model with concordance of history as the outcome variable. RESULTS: One hundred fifty-six (90%) of the 173 patients enrolled in our study indicated that their health care provider had discussed with them the reason for ordering the sonographic examination. The histories provided by the patient and health care provider were concordant in 134 (77%) of 173 cases. The histories provided by the patient and health care provider were more likely to be concordant if the patient's insurance was a managed care plan or if the patient had a college or graduate level education, had been cared for by the same health care provider for more than 2 years, or had been seen by a female health care provider. Concordance of history was not associated with a higher incidence of abnormal sonographic findings. CONCLUSIONS: It appears that health care providers, despite increased demands on their time, adequately discuss with their patients the reasons for ordering a pelvic sonographic examination. However, our study suggests that health care providers may need to spend additional time with patients whose education is limited and that male physicians may need to pay particular attention to their communication with female patients.

Adult↗
PubMed2000

Expression of the integrin alpha8beta1 during pulmonary and hepatic fibrosis.

The fibrotic response after diverse forms of injury is characterized by the accumulation of extracellular matrix proteins, proliferation of myofibroblast-like cells, and organ contraction. Myofibroblasts are key effector cells in the development of the fibrotic response. They contribute to fibrosis through both increased cell number (proliferation) and enhanced matrix synthesis. Integrins, a class of cell adhesion molecules, are mediators of cell-extracellular matrix protein interactions that are important in the proliferative and migratory response of cells to matrix proteins. We have previously cloned the human integrin subunit alpha8, documented its high expression in lung tissue, and established it as a receptor for the matrix proteins fibronectin, vitronectin, and tenascin. We now demonstrate that alveolar interstitial cells are the primary cell type expressing alpha8beta1 in the lung parenchyma. Expression of alpha8beta1 is concentrated primarily along the thinned extensions of cells and at the tips of filopodia. Because of its unique distribution in alveolar interstitial cells, we hypothesized that it may play a role in the fibrotic response after injury. In bleomycin-induced pulmonary fibrosis, there is increased expression of alpha8beta1 by interstitial fibroblasts, the majority of which coexpress alpha smooth muscle actin, a marker of tissue myofibroblasts. To establish a more general role for alpha8beta1 during organ fibrosis, we further examined its expression in two rat models of liver fibrosis. During hepatic injury due to either carbon tetrachloride injury or bile duct ligation, we demonstrate de novo expression of alpha8beta1 in activated hepatic stellate cells, the myofibroblast equivalent in liver. Taken together, the data localize alpha8beta1 to myofibroblast-like cells during wound healing and suggest that signal transduction through the alpha8beta1 integrin may contribute to the fibrotic response of organs to injury.

Animals↗
PubMed2000

Factors related to sleep disturbance in older adults experiencing knee pain or knee pain with radiographic evidence of knee osteoarthritis.

OBJECTIVES: To describe the types and frequencies of sleep complaints and the biopsychosocial factors associated with sleep disturbance in a large community sample of older adults experiencing knee pain or knee pain with radiographic evidence of knee osteoarthritis (OA). DESIGN: Baseline analyses of an observational prospective study. SETTING AND PARTICIPANTS: Participants were 429 men and women aged 65 years and older experiencing knee pain or knee pain with radiographic evidence of OA enrolled in the Observational Arthritis Study in Seniors (OASIS). MEASUREMENTS: Demographic variables (age, gender, ethnicity, education), health (X-rays of knee rated for OA severity, medical conditions, medication use, smoking status, body mass index, self-rated health), physical functioning (self-rated physical functioning, physical performance), knee pain, and psychosocial functioning (social support, depression) were measured. RESULTS: Problems with sleep onset, sleep maintenance, and early morning awakenings occurred at least weekly among 31%, 81%, and 51% of participants, respectively. Bivariate correlates of greater sleep disturbance in those with OA were less education, cardiovascular disease, more arthritic joints, poorer self-rated health, poorer physical functioning, poorer physical performance, knee pain, depression, and less social support. In regression analyses, each set of variables representing the domains of health, physical functioning, pain, and psychosocial functioning contributed to the prediction of sleep disturbance beyond the demographic set. Finally, in a simultaneous model, white race (trend, P = .06), poorer self-rated health, poorer physical functioning, and depressive symptoms were predictive of sleep disturbance. CONCLUSIONS: Sleep disturbance is common in older adults experiencing knee pain or knee pain with radiographic evidence of OA and is best understood through the consideration of demographic, physical health, physical functioning, pain, and psychosocial variables. Interventions that take into account the multidetermined nature of sleep disturbance in knee pain or knee OA are most likely to be successful.

Activities of Daily Living↗
PubMed2000

Luteoma of pregnancy: sonographic findings in two cases.

Luteoma of pregnancy is a rare nonneoplastic tumor-like mass of the ovary that emerges during pregnancy and regresses spontaneously after delivery. It is usually asymptomatic and is found incidentally during a cesarean section or postpartum tubal ligation. However, luteomas can be hormonally active, with production of androgens resulting in maternal and fetal hirsutism and virilization. Less than 200 cases have been described in the literature, and none in radiologic journals. Recognition of this entity is important so that unnecessary oophorectomy, with concomitant risk to both the patient and the fetus, is avoided. In this report, we describe two cases of luteoma of pregnancy. The first case documents sequential ultrasonographic demonstration of a presumed luteoma of pregnancy in a patient who was seen with hirsutism during a second trimester pregnancy. The luteoma, serum androgen levels, and patient's condition improved after delivery. This case is unique in that although the mass significantly decreased in size post partum, it continued to be visualized 14 months post partum. The second case illustrates the pronounced cystic appearance that these classically described solid lesions can demonstrate because of extensive necrosis.

Adult↗
PubMed2000

Neurolisteriosis presenting as recurrent transient ischemic attacks.

An elderly man experienced recurrent transient episodes of right arm weakness and expressive aphasia. He was initially treated with aspirin and then with coumadin. Thirteen days after initial presentation, he became febrile and had signs of meningitis. The illness progressed relentlessly to death 9 weeks after admission to the hospital. Necropsy showed prominent meningitis with vasculitis extending into the left frontal lobe. Polymerase chain reaction identified the organism as Listeria monocytogenes.

Aged↗
PubMed1999

Gender differences in blood thrombogenicity in hyperlipidemic patients and response to pravastatin.

Thrombotic risk in hyperlipidemic women and its response to lipid therapy is unknown. We prospectively studied 28 men and 29 women with high low-density lipoprotein (LDL) cholesterol during 6 months of therapy with pravastatin. Women had significantly higher high-density lipoprotein (HDL) cholesterol (54.2 +/- 1.7 vs 39.5 +/- 2.2 mg/dl, p <0.01), lower prevalence of coronary artery disease (41% vs 67%, p = 0.04), and otherwise similar baseline characteristics compared with men. Both genders achieved a 33% reduction in LDL at 6 weeks (188 +/- 6 to 133 +/- 5 mg/dl) and maintained similar LDL levels throughout the study. Systemic hemostatic markers and thrombus formation under dynamic flow conditions were evaluated at baseline, and at 3 and 6 months of follow-up. Prothrombin fragment F1.2, a marker of thrombin generation, was higher in women versus men at baseline (2.4 +/- 0.2 vs 1.4 +/- 0.3 nmol/L, p = 0.02). The levels decreased in women to 2.0 +/- 0.3 nmol/L at 3 months and to 1.6 +/- 0.2 nmol/L at 6 months (p <0.045, analysis of variance), whereas it remained unchanged in men. Plasminogen activator inhibitor-I significantly decreased at 3 and 6 months of follow-up: by 12.6% and 18.7%, respectively, in women, and by 18.8% and 23.5%, respectively, in men. Similarly, tissue plasminogen activator decreased significantly by 7.4% in women and 11.8% in men at 6 months compared with baseline. Fibrinogen showed an increase in both genders at follow-up. Thrombus formation was similar at baseline between the 2 genders, and decreased at 3 and 6 months compared with baseline by 12.5% and 29.5% in women, and by 18.6% and 19.4% in men (p <0.04 at 6 months vs baseline in both men and women). Other markers, including C-reactive protein, fibrinopeptide A, D-dimer, and factor VIIa, did not differ between genders and did not change with therapy. Thus, despite higher HDL, and lower incidence of coronary disease, women with high LDL had a comparable thrombotic and/or fibrinolytic profile to men and even evidence of increased thrombin generation at baseline. Blood thrombogenicity was reduced with pravastatin in both genders; in addition, thrombin generation was gradually reduced in women to a level similar to that of men by 6 months of follow-up.

Aged↗
PubMed1999

Antenatal diagnosis of fetal hepatic hemangioma treated with maternal corticosteroids.

BACKGROUND: Infantile hepatic hemangioma is a benign liver tumor with potentially fatal complications. Response of these lesions to steroid therapy has been well documented in infants. Successful antenatal treatment of a fetal hepatic hemangioma with maternal corticosteroids is reported. CASE: A 36-year-old woman, gravida 2, para 1, had an ultrasound at 17 weeks which showed a fetal hepatic hemangioma. Because of increase of the tumor and enlarged fetal heart, maternal oral corticosteroid therapy was commenced at 28 weeks, which progressively decreased the mass. The infant was delivered at 36 weeks with no evidence of heart failure, and at 7 months the tumor was barely seen on ultrasound. CONCLUSION: When an enlarging fetal hepatic hemangioma is detected antenatally, maternal corticosteroid therapy should be considered.

Adult↗
PubMed1999

Central nervous system abnormalities assessed with prenatal magnetic resonance imaging.

OBJECTIVE: To determine the frequency at which magnetic resonance imaging (MRI) provides additional information in fetuses with suspected central nervous system (CNS) abnormalities on ultrasound. METHODS: Between May 1, 1996, and March 26, 1999, 83 women with 90 fetuses (including seven sets of live twins) had 91 ultrasonographic and MRI examinations of the fetal CNS. Eight women were studied twice, one for two different indications. If referrals came from outside our institution, a confirmatory sonogram was obtained. Indications for examination were ventriculomegaly (n = 25), suspected neural tube defect (n = 16), arachnoid cyst (n = 12), large cisterna magna (n = 11), and miscellaneous indications (n = 20). RESULTS: Magnetic resonance imaging findings led to changed diagnoses in 26 (40%) of 66 fetuses with abnormal confirmatory sonograms. Magnetic resonance imaging findings not found by ultrasound included partial or complete agenesis of the corpus callosum (n = 11), porencephaly (n = 6), hemorrhage (n = 5), tethered cord (n = 3), cortical gyral abnormality (n = 2), cortical cleft (n = 2), midbrain abnormality (n = 2), and partial or complete agenesis of the septi pellucidi (n = 3), as well as holoprosencephaly, cerebellar hypoplasia, subependymal and cortical tubers, vascular malformation, and vermian cysts (one case each). Abnormalities better delineated by MRI than ultrasound included three cephaloceles, a dural arteriovenous malformation, one distal sacral neural tube defect, and the mass effect of three arachnoid cysts. That information was used to alter patient counseling and at times management. CONCLUSION: When a CNS anomaly is detected by sonography or suspected on ultrasound, MRI findings might lead to altered diagnosis and patient counseling.

Central Nervous System↗